KEN CROSWELL'S ARTICLES BY DATE

February 2025: Gaia Begins a Black Hole Revolution: Most black holes are quiet, and the Gaia spacecraft is starting to find them.

November 1, 2024: A Distant Quasar's Black Hole is Oddly Huge for its Galaxy*: The black hole powering the quasar has a record mass relative to the stars of the host galaxy.

October 11, 2024: Saturn's First Trojan Asteroid Has Finally Been Discovered*: All four giant planets now have known asteroids sharing their orbits.

September 2024: Who First Described the Comet Belt Just Beyond Neptune? It's time the so-called Kuiper Belt was finally rebranded.

August 20, 2024: The Nearest Midsized Black Hole Might Instead Be a Horde of Lightweights*: A claim of an intermediate-mass black hole in a Milky Way star cluster comes under scrutiny.

August 16, 2024: A Distant Quasar May Be Zapping All Galaxies Around Itself*: Star formation has ceased within 16 million light-years of the quasar.

August 7, 2024: Extreme Quasars Illuminate the Fast Lives of the First Black Holes: Recent discoveries of record-breaking quasars have pushed the boundaries of our understanding.

July 25, 2024: The North Star is Much Heavier Than Previously Thought*: Polaris is nearly 50 percent more massive than an earlier study found.

July 15, 2024: Sulfur Was Key to the First Water on Earth*: The find suggests all rocky planets get wet soon after birth, boosting the chances for life.

May 2024: The Story of Wolf 359: A little red sun in Leo was once the least luminous star known.

February 2, 2024: Marsquakes Shake Up Views of the Red Planet's Deep Interior: The InSight spacecraft's seismometer sizes up the Martian crust, mantle, and core.

December 2023: The Drama Next Door [cover story]: The Andromeda Galaxy is a giant spiral like the Milky Way but has had a surprisingly different, and tumultuous, past.

August 16, 2023: A Brightness Gap Exposes the Inner Lives of Red Dwarf Stars: Red dwarfs can pulsate.

August 2023: Dawn of the Milky Way: New observations are unveiling the earliest years of our Galaxy.

July 2023: When Red Giants Were Young: One hundred years ago astronomers thought large, cool stars were destined to become stars like the Sun.

April 2023: The Little Stars That Can: Surprising new observations reveal novae forging a lightweight metal whose price keeps going up and up.

March 8, 2023: An Ambitious New Mission Seeks the Origin of the Moons of Mars: Are Phobos and Deimos Captured Asteroids, or Did They Form After a Large Object Hit the Red Planet?

February 23, 2023: The Milky Way May Be Spawning Many More Stars than Astronomers Had Thought: Gamma rays reveal the Galaxy's star-making power.

February 2023: The Cepheus Spur: A newly named feature in our Galaxy drapes distant luminaries across the northern sky from Cepheus and Camelopardalis to Auriga, Gemini, Taurus, and Orion.

December 2022: The First White Dwarf [cover story]: The road to discovering a new type of star was long and winding.

October 21, 2022: Most Stars May Have Much More Time to Form Planets Than Previously Thought*: Planet-making disks may survive around many young stars for 5 to 10 million years.

October 20, 2022: Seeking Answers, Planetary Scientists Plot a Return to the Nearest Ice Giant: Uranus beckons.

September 21, 2022: A Protogalaxy in the Milky Way May Be Our Galaxy's Original Nucleus*: It's the kernel around which the Milky Way first formed.

July 22, 2022: The Heaviest Neutron Star on Record Has 2.35 Times the Mass of the Sun*: The discovery helps refine the dividing line between neutron stars and black holes.

June 16, 2022: Neutrinos Hint the Sun Has More Carbon and Nitrogen than Previously Thought*: Figuring out our star’s makeup is crucial for understanding the entire universe.

June 2022: Who Really Discovered Stellar Proper Motion? Contrary to many books and articles, the answer isn't who you think.

May 2022: The Lithium Problem: Why do the oldest stars have only a third as much lithium as big bang predictions say they should?

April 28, 2022: Nearby Primitive Galaxies Offer a Window into the Early Universe: Galaxies just beyond the Local Group illuminate the nature of the first stars.

April 20, 2022: "Goldilocks Stars" May Pose Problems for Any Nearby Habitable Planets*: Far-ultraviolet radiation from orange dwarfs could endanger planetary atmospheres.

April 1, 2022: When the Magellanic Clouds Cozy Up to Each Other, Stars Are Born: Five synchronized peaks of star formation reveal the galaxies' most intimate encounters.

March 23, 2022: Here's the Best Timeline Yet for the Milky Way's Big Events: Our Galaxy formed its original disk 2 billion years before its stellar halo.

March 8, 2022: A New Image Captures Enormous Gas Rings Encircling an Aging Red Star*: The star is losing mass as it transforms into a white dwarf star.

February 14, 2022: How Hot Jupiters May Get Their Weirdly Tight Orbits*: Stars and neighboring planets can fling giant worlds toward their suns.

January 18, 2022: Astronomers Uncover New Way to Measure the Speed of Stars: New observations now allow the seemingly impossible: determining how quickly some stars move toward us without measuring their Doppler shifts.

October 5, 2021: Astronomers Are Redrawing Our Corner of the Milky Way: Remarkable new observations are revealing the starry landscape of our Galactic neighborhood and our place within it.

September 13, 2021: A Supernova's Delayed Reappearance Could Pin Down How Fast the Universe Expands: The catch: we have to wait until about 2037 for an answer.

August 23, 2021: Here's How Cool a Star Can Be and Still Achieve Lasting Success*: The motions of nearby stars reveal the boundary between red dwarfs and brown dwarfs.

July 6, 2021: A Shadowy Birthplace May Explain Jupiter's Strange Chemistry: A frigid planetary nursery could account for the gas giant’s peculiar atmospheric composition.

June 14, 2021: Most Planets on Tilted Orbits Pass Over the Poles of Their Suns*: The surprising discovery may reveal how misaligned worlds arise.

May 6, 2021: Saturn Has a Fuzzy Core, Spread Over More Than Half the Planet's Diameter*: A wave in one of the rings reveals the size and composition of the planet's core.

April 27, 2021: Voyager Still Breaking Barriers Decades After Launch: As Voyagers 1 and 2 continue their epic journeys through interstellar space, they're resolving past controversies and even helping to spark a new one: the true shape of the heliosphere.

April 9, 2021: A Record-Breaking, Oxygen-Starved Galaxy May Be Full of Gigantic Stars' Shrapnel*: The pristine galaxy provides a glimpse at conditions that prevailed in the early universe.

March 26, 2021: The "USS Jellyfish" Emits Strange Radio Waves from a Distant Galaxy Cluster: Spanning 1.2 million light-years, the entity broadcasts a never-before-seen pattern of radio waves.

March 17, 2021: A Gargantuan Supernova Remnant Looks 40 Times Bigger than the Full Moon*: From Earth's perspective, it's the largest cloud of debris ever seen from an exploded star.

February 12, 2021: The Number of Milky Way Nova Explosions Per Year Has Been Pinned Down*: Every year about four dozen of these stellar eruptions occur in our Galaxy.

February 2021: The Story of T Tauri: An infant star in Taurus helped reveal a truth once thought radical: the universe still makes new stars.

January 26, 2021: Tracing Gold's Cosmic Origin Story: Astronomers thought they had finally figured out where the gold, platinum, and other heavy elements in the universe came from. In light of recent results, they’re not so sure.

December 14, 2020: The Milky Way's Central Black Hole May Have Turned Nearby Red Giant Stars Blue: A powerful blast from the supermassive black hole may explain a lack of large, red stars there.

December 5, 2020: Origins of a Mighty Meteor Shower [cover story]: How does a space rock make such a stunning display of shooting stars?

November 30, 2020: Runaway Stars May Create the Mysterious Ultraviolet Glow Around Some Galaxies*: The bright, young stars are located in regions where gas is too tenuous for new stars to form.

November 5, 2020: The Milky Way Makes Little Galaxies Bloom, Then Snuffs Them Out*: Dwarf spheroidal galaxies light up with newborn stars when first approaching our Galaxy.

September 28, 2020: The Milky Way's Most Massive Star Cluster May Have Eaten a Smaller Cluster: Observations of newfound stars suggest how the gathering of stars at the Galaxy's core grew so big.

July 24, 2020: The Closest Star Cluster to Earth is in Its Death Throes*: Stars in the Hyades cluster are dashing past one another so fast it will disintegrate in only 30 million years.

July 1, 2020: Was Jupiter Born Beyond the Current Orbits of Neptune and Pluto? Conventional theory says Jupiter was born where it is now. Two groups of researchers working independently have proposed an intriguing alternative.

June 25, 2020: An Elemental Problem with the Sun: For two decades astronomers have been arguing over exactly how much carbon, nitrogen, and especially oxygen the Sun has--with implications for the entire universe.

May 8, 2020: How Tiny "Dead" Galaxies Get Their Groove Back and Make Stars Again*: Gas falling into a dwarf galaxy must fight the galaxy's own stars before making new ones.

April 21, 2020: High-Speed Collisions Prevent Star Formation in Galactic Bars: Simulations of the stunning barred spiral galaxy NGC 1300 explain why its bar fails to sparkle with newborn stars.

March 23, 2020: Astronomers Have Found the Edge of the Milky Way*: Our Galaxy's total diameter is a whopping 1.9 million light-years.

February 18, 2020: Molecular Oxygen Spotted Beyond the Milky Way for the First Time: Sought for decades, the elusive molecule turned up in a quasar more than half a billion light-years away.

February 2020: Dwarf Carbon Stars: Stars that shouldn't even exist may soon offer new clues to the ancient universe and the Galaxy's birth.

January 21, 2020: A Massive Star Dies Without a Bang: Evidence emerges that not all red supergiants explode, raising the possibility that Betelgeuse will never go supernova.

December 11, 2019: Space is the Place for Impossible Molecules: Molecules containing noble gases don't form naturally on Earth. But they do in the interstellar medium.

December 2019: Uranus and Neptune: The Neglected Planets [cover story]: Decades after a lone spacecraft flew by, the solar system's ice giants and their many moons still guard plenty of secrets.

November 2019: Mapping the Milky Way [cover story]: Recent years have seen tremendous strides in unraveling the Galaxy's spiral arms, and the next decade promises the best maps ever made of our celestial home.

May 31, 2019: The Mighty Milky Way: Our Galaxy is far bigger, brighter, and more massive than most others.

April 2019: Spendthrift Spirals: The great spiral galaxies that adorn the modern universe are running out of gas and may someday lose their beautiful shapes.

December 2018: The Fastest Stars Escaping the Galaxy: Exploding white dwarfs can hurl their companions away at record speed, dooming them to roam intergalactic space for all eternity.

October 2018: The Void Next Door [cover story]: An enormous region of darkness starts on our doorstep, giving astronomers their best chance to probe one of these gigantic cosmic structures.

April 18, 2018: Shredded Galaxy Is Disintegrating Before Our Eyes After Smash-Up*: After collision with a neighbouring galaxy, the Small Magellanic Cloud may lose its ability to spawn new stars.

April 2018: The Little Galaxies That Can: Star-making dwarf galaxies with just a trace of oxygen provide insight into the nature of the first galaxies, how they spawned their stars, and even the big bang itself.

November 13, 2017: We Found Our Galactic Twin 180 Million Light-Years Away*: A galactic trio looks remarkably like the Milky Way and its two brightest companions, the Magellanic Clouds.

October 31, 2017: Astronomers Race to Learn from First Interstellar Asteroid Ever Seen: For the first time, we've seen an asteroid from another solar system visit our own.

October 11, 2017: Pluto's Egg-Shaped Neighbor Haumea Has a Ring No One Expected: It's the farthest ring ever seen in our solar system.

September 8, 2017: Low-Oxygen Dwarf Galaxy Shows Us How the Early Universe Looked: A star-forming galaxy with a record-breaking oxygen abundance probes conditions shortly after the big bang.

September 4, 2017: Some of Uranus's Small Moons Are Doomed to Collide: The first measurement of the mass of a small moon of Uranus suggests it will be obliterated after smashing into another satellite in the next million years.

August 31, 2017: Spiralling Arms Help Spread Oxygen Around for Future Planets*: The spiral arms of a galaxy named NGC 1365 contain 60 percent more oxygen than the space between, the most extreme variation ever seen.

May 25, 2017: Strange Cosmic Radio Burst Pinned Down to Giant Stellar Nursery*: A young neutron star is probably the source of a strange repeating signal previously tracked to a dwarf galaxy 2.4 billion light-years away.

November 29, 2016: Proxima Centauri Really Does Orbit Its Two Bright Neighbours*: After a century of speculation, astronomers confirm that Proxima Centauri revolves around Alpha Centauri A and B.

November 21, 2016: A Dash of Hydrogen and Methane Could Have Kept Mars Warm*: New calculations may solve the mystery of how ancient Mars got warm enough for rivers to flow.

October 21, 2016: Double Star May Light Up the Sky as Rare Red Nova in Six Years*: New observations of KIC 9832227 show it's on track to become a rare “red nova.”

October 14, 2016: Uranus Might Have Two Dark Moons We've Never Seen Before*: Newly detected wavy patterns in two of Uranus's rings suggest the possible presence of two small, unseen satellites.

October 4, 2016: Super-Dim Galaxy May Be One of Hundreds Orbiting the Milky Way*: What may be the least luminous galaxy ever seen suggests our Galaxy has hundreds of equally dim satellites.

September 29, 2016: Milky Way's Baby Brother Caught Copying Its Star-Shredding Habit*: The Large Magellanic Cloud is tearing apart a star cluster it may have stolen from another galaxy.

September 15, 2016: Kamikaze Galaxy Explodes After Diving Into the Milky Way*: The Hercules dwarf has the most elliptical orbit ever seen for a Milky Way satellite galaxy.

August 31, 2016: Gang of Gas Giants May Have Tilted Distant Solar System*: Astronomers pin down the likely culprit behind the first tilted solar system ever found.

August 19, 2016: Hyperactive Galaxy Could Run Out of Gas in Just 8 Million Years*: Nearby "starburst" galaxy is using up and blowing out far more gas than it takes it, astronomers warn.

August 15, 2016: Mating Stars Hide Their Modesty Behind a Thick Veil of Dust: A torus of thick dust surrounds two stars that recently merged into one.

July 27, 2016: Torn-Apart Galaxy May Be Exacting Revenge on the Milky Way*: The Sagittarius dwarf was massive enough to warp the galaxy that's tearing it apart.

July 26, 2016: The Milky Way's Dark Twin Revealed*: An almost invisible galaxy weighs as much as our own.

May 13, 2016: Cannibal Stars Explode Violently – as Predicted by Darwin’s Son*: Big star eats little star.

April 22, 2016: The Mystery of Phantom Galaxies May Soon Be Solved: A new theory says these mysterious "ultradiffuse" galaxies are dwarfs born in a whirl.

April 14, 2016: Never-Before-Seen Galaxy Spotted Orbiting the Milky Way*: The Crater 2 dwarf galaxy is our Galaxy's fourth largest satellite.

March 22, 2016: Ghostly Galaxies Are Light on Stars But Heavy on Dark Matter: The first measurement of an ultradiffuse galaxy's mass finds that dark matter makes up more than 99.96 percent of its mass.

January 27, 2016: Record-Breaking Double Star May Be Cannibalising Itself*: An extreme binary “eclipses” Epsilon Aurigae by having an orbital period more than twice as long.

December 15, 2015: Prodigal Gas Cloud Was Born in Milky Way and Is Crashing Back in*: Astronomers pinpoint the birthplace of a mysterious cloud in space.

December 15, 2015: Little Galaxy's Own Stars Cast 95 Per Cent of Its Oxygen Away*: It's not easy being a little galaxy.

December 8, 2015: Super Spiral Galaxies Amaze Astronomers*: A new breed of giants raises questions about how the biggest galaxies arise.

September 18, 2015: Good News, Earthlings: The Planet Mercury Probably Won't Kill Us: Mercury may crash into Venus, but Earth is probably safe, if a new study is right.

June 8, 2015: 814 Ghostly Galaxies Found in Famous Cluster*: Huge number may yield insight into how these galactic phantoms formed.

April 2015: Galactic Ghosts: Ghostly galaxies turn up in the Coma cluster.

December 19, 2014: Clocking the Hot Gas Gushing from the Milky Way's Core*: New observations of the Fermi bubbles indicate the Galaxy's core erupted 2.5 to 4 million years ago.

September 3, 2014: How To Find Your Way Home from Deep Space: Astronomers unfurl a map more than a billion light-years across.

August 28, 2014: Astronomers Measure Precise Distance to Controversial Star Cluster: But a top scientist blasts the result.

August 27, 2014: Neutrinos from Sun's Main Nuclear Reaction Detected: Numbers agree with the standard solar model.

August 25, 2014: Water Clouds Tentatively Detected Just 7 Light-Years from Earth*: They're the first water clouds seen beyond our solar system.

August 20, 2014: Nearby Galaxy May Be Victim of Dark Matter Hit-and-Run: A dark subhalo may have punched a hole in spiral galaxy NGC 247.

August 18, 2014: Nearby Galaxy Harbors Rarest Type of Black Hole: M82's black hole is 400 times as massive as the Sun.

August 11, 2014: Far Out: The Most Distant Star in the Milky Way: A star 890,000 light-years away patrols our Galactic frontier.

July 8, 2014: Hubble Finds Vast Reservoir of Gas Near the Milky Way: The Magellanic Stream may solve our Galaxy's impending gas shortage.

June 2, 2014: A Stellar Discovery on the Far Side: Five remarkable stars on the other side of our Galaxy promise new insight into the outer reaches of our home turf.

April 4, 2014: Star Birth Sparked at the Galaxy's Edge: Gas from another galaxy is hitting our own, triggering the birth of bright new stars and adding fresh luster to the Milky Way.

March 7, 2014: Found: The Fastest Approaching Object in the Universe: It has a record-setting blueshift of 1,026 kilometers per second.

January 29, 2014: Nearby Brown Dwarf Has Partly Cloudy Skies: Clues emerge to weather patterns on "hot Jupiters".

January 23, 2014: Proxima's Unprecedented Passage: When Stars Align: The Sun's closest stellar neighbor will soon reveal its mass--and possibly its planets--when it passes in front of a distant star.

January 10, 2014: A Star at the Edge of Eternity: A Saturn-sized star just 40 light-years away will outlive nearly all of its peers.

January 6, 2014: Pulsar Will Put the Test to General Relativity: Trio of dead stars will subject Einstein's strong equivalence principle to its most stringest test ever.

December 12, 2013: First Noble Gas Molecules Found in Space: Argon hydride spotted in remnant of exploded star.

November 22, 2013: The Galaxy Collision Next Door*: Two dwarf galaxies may have smashed together in our Local Group, sparking the nearest "starburst."

November 21, 2013: Oldest Minerals From Mars Found on Earth: New Martian meteorite sheds light on the red planet's earliest years.

November 1, 2013: Nearest Newborn Stars Discovered: A double star just 20 light-years from Earth is surprisingly young, offering bright prospects for planet hunters.

October 23, 2013: Farthest Confirmed Galaxy Is a Prolific Star Creator: It shone just 700 million years after the big bang.

October 17, 2013: Kepler Finds the First Tilted Solar System: Two planets circle their aging sun at a 45-degree angle.

October 3, 2013: Fomalhaut Is Triple*: The bright star has a red dwarf companion--2.5 light-years away.

October 2, 2013: Supervolcanoes Spotted on Mars: Colossal eruptions rocked the red planet's youth.

September 30, 2013: Air Apparent: Pluto's Eternal Atmosphere: New observations suggest the small world's air never vanishes.

August 30, 2013: The Milky Way Supernova You've Never Heard Of*: A newly measured distance to stellar debris in the northern sky ties it more firmly to an explosion observers saw in 1181.

August 16, 2013: Elderly Couple Kicked Out of the Galaxy: Astronomers find the first old stars escaping from the Milky Way.

July 31, 2013: Tides Control the Geysers of Enceladus: Their strength depends on the moon's distance from Saturn.

July 15, 2013: New Moon Over Neptune: Hubble spots a new satellite around the distant giant planet.

July 2, 2013: Captain Kirk Is Defeated at Pluto: William Shatner loses his battle to name a distant moon Vulcan.

May 29, 2013: Venus: Doomed From the Start? The nearest planet probably never had oceans or life.

May 22, 2013: Why Some Galaxies Age Before Their Time: Ancient collision may explain why some young galaxies look old.

May 21, 2013: A Tail of Two Galaxies*: A dual origin for the Magellanic Stream?

May 13, 2013: Saturn Is Shaking Its Rings*: Oscillations inside the giant planet perturb its rings, promising new clues to the nature of its enormous interior.

May 2, 2013: Diamond Planets Get Even More Precious: Carbon planets are a lot rarer than had been thought.

May 2013: Tadpoles in Space: Exotic galaxies may provide snapshots of the Milky Way's youth.

April 1, 2013: Gentle or Jumping? The Varied Lives of Hot Jupiters*: A newborn star's iron abundance foretells whether its gas giants face a violent future.

April 2013: Wanted: New Worlds Beyond Pluto: Scientists work to keep an intrepid spacecraft busy.

March 20, 2013: Star Performers: The Magellanic Clouds: Two intrepid galaxies dash past the Milky Way--and dazzle astronomers.

March 13, 2013: "Cold" Hydrogen Molecules Found on Hot Stars*: Surprise discovery may probe the conditions on white dwarfs.

December 18, 2012: Another Earth 12 Light-Years Away?: Five planets may orbit Tau Ceti.

December 3, 2012: Galaxy Grande: Milky Way May Be More Massive Than Thought*: Hubble observations of a speedy galaxy weigh on the Milky Way and indicate that our Galaxy is at least a trillion times as massive as the Sun.

December 3, 2012: Older Vega Is Mature Enough for Primitive Life*: The star of Contact is older than had been thought.

November 28, 2012: Gargantuan Black Hole Occupies Modest Galaxy: It's one of the biggest black holes ever seen.

November 2012: Pluto's Revenge: Hubble Finds a Fifth Moon: Discovery boosts Pluto's planetary cred.

October 19, 2012: The Return of a Great Nineteenth-Century Meteor Shower*: Long thought nearly extinct, the Andromedid meteor shower staged a surprise outburst last December—and may return in 2018 and 2023.

July 31, 2012: Did Runaway Stars Reionize the Ancient Universe?*: Hot stars booted out of their galactic homes may be responsible for creating the conditions that led to today's universe.

July 18, 2012: Hubble Spots the Farthest Spiral Galaxy Ever Seen: It flaunted its spiral arms just 3 billion years after the big bang.

July 4, 2012: Poof! Planet-Forming Disk Vanishes Into Thin Air: The same cosmic mystery may have occurred in our solar system.

June 6, 2012: Pluto's Moons Offer Hints of Alien Worlds*: The distant satellites may show how planets orbit double stars.

May 30, 2012: The Milky Way's Oldest and Wisest Stars: An astronomer invents a new technique to trace the origins of our Galaxy.

May 24, 2012: How Many Stars Never Make the Big Time?*: Search for brown dwarfs reveals the odds of stellar success.

May 7, 2012: Hot Jupiters Are Loners: Gas giants orbiting next to their suns have no close planetary neighbors.

May 2, 2012: Giant Black Hole Shreds and Swallows Helpless Star: Astronomers watch the drama unfold from 2.1 billion light-years away.

April 24, 2012: Galaxies Defy Astronomers' Expectations: Galaxies formed stars differently in the early universe.

April 7, 2012: Tides Turn Some "Habitable" Planets Into Hellish Hothouses*: Planets close to small red dwarfs may be "tidal Venuses."

March 22, 2012: One Black Hole Won't Ruin Your Day: If a primordial black hole hits Earth, you'll probably feel just fine.

February 21, 2012: Some Planets Are Alien Invaders*: Billions of stars in our Galaxy may have captured their most distant worlds.

February 3, 2012: Double Star Hosts Ancient World*: It's 2 billion years older than Earth.

January 6, 2012: The Star That Never Was*: Stardom is just a pipe dream.

December 16, 2011: Is Jupiter Eating Its Own Heart?*: Some gas giant planets may have destroyed their cores.

December 14, 2011: Danger: Black Hole Dead Ahead!: What may be a gas cloud is hurtling toward the Galaxy's biggest black hole.

December 7, 2011: Giant Stars Bare Their Whirling Hearts: Their cores spins much faster than their surfaces.

November 29, 2011: Starburst in Andromeda*: The giant Andromeda Galaxy owes a bit of its beauty to a galactic encounter.

November 11, 2011: The Fastest Spinning Normal Star*: It spins 300 times faster than the Sun.

November 10, 2011: Pristine Relics of the Big Bang Spotted: Two distant gas clouds appear untouched by stars.

September 6, 2011: Baby Star Found on Earth's Doorstep: The nearest pre-main-sequence star ever found may sport glowing planets.

August 12, 2011: "Earth-Mars" Collision May Have Hit Alien Solar System*: Did something whack a dim star's planet--and create a new moon?

August 8, 2011: The Fate of the First Black Hole*: The black hole of Cygnus X-1 will likely separate from its long-suffering partner.

July 22, 2011: The Milky Way's Dimmest Star Cluster*: Segue 3 ekes out just 90 Suns' worth of light.

June 28, 2011: Famous Black Hole Confirmed After Forty Years*: The first parallax to Cygnus X-1 reveals that it must contain a black hole.

June 25, 2011: Busted! Nearby Galaxy Is a Stellar Thief*: The Large Magellanic Cloud snatched stars from its long-time companion.

June 14, 2011: Galactic Hit and Run*: Astronomers reconstruct a celestial accident.

May 12, 2011: Far-out Earths Could Support Alien Life*: A life-bearing planet can exist far from its star--if its air abounds with hydrogen.

April 12, 2011: Do Spiral Galaxies Form from the Inside Out?*: Distant spiral sheds light on galaxy formation.

March 21, 2011: Can Dying Stars Support Life?: White dwarfs may have habitable planets.

March 12, 2011: Newly Found Brown Dwarf Is Ultracool*: It's room temperature.

March 8, 2011: Distant Galaxy Helped Relight the Universe*: It began forming stars only 150 to 300 million years after the big bang.

February 10, 2011: Future of Cosmology Looks Bright in a Dark Universe: Cosmologists will still be able to do their job--even a trillion years from now.

January 14, 2011: Hot World Breaks Record*: It's the hottest planet yet.

December 7, 2010: Dancing Stars Turn on the Red Light*: Two stars merge and trigger a rare type of nova.

December 2010: Star Struck: Astronomers turn their telescopes to the unbounded beauty of the Milky Way.

November 19, 2010: Can the Sun's Siblings Be Found?*: The Milky Way's spiral arms may have scattered the Sun's siblings hither and yon.

September/October 2010: Wrong-Way Planets: Many extrasolar planets orbit their stars against the grain.

September 1, 2010: Tilting Stars May Explain Backward Planets*: Stellar flips may explain some wrong-way planets.

August 26, 2010: Galactic Collisions Spread The Wealth*: When galaxies collide, regions rich and poor in metals mix it up.

August 12, 2010: Stars Steal Their Planet's Moons: Hot Jupiters may be moonless.

July 2, 2010: Planets "Sing" in Three-Part Harmony*: Astronomers discover the first three-planet resonance--around a star just 15 light-years away.

June 22, 2010: Speedy Star Points to More Massive Milky Way*: The fastest halo star ever seen may boost estimates of our Galaxy's mass.

June 2010: Why Jupiter's Big Moons Outnumber Saturn's: Jupiter 4, Saturn 1. Why?

May 25, 2010: Supermassive Black Holes Reveal a Surprising Clue*: A startling correlation between the mass of a galaxy's central black hole and the number of globular clusters may give insights into galactic evolution.

April 9, 2010: "Dark Sun" Is One of Our Nearest Neighbors: A newfound star less than 10 light-years from Earth appears to be the closest brown dwarf ever detected.

February 18, 2010: Ninth Rock From the Sun: It's time for a new and improved definition of "planet"--one that restores Pluto to its former glory.

November 12, 2009: A Star From Another Galaxy*: One of our nearest stellar neighbors--Kapteyn's Star, just 13 light-years from Earth--probably originated in another galaxy.

October 2009: Giant Molecular Cloud in Solar Neighborhood: The California Nebula has a dark secret.

September 26, 2009: No Home For Life in the Galactic Outer Suburbs*: If the Sun had been born near the edge of the Milky Way, we probably wouldn't exist.

September 2009: Galaxy Smash-Up Revealed Next Door: The Small Magellanic Cloud suffered a big collision 7.5 billion years ago.

August 13, 2009: The Milky Way's Secret Companion?*: A large satellite galaxy may be lurking next to ours, hidden from sight.

June 27, 2009: How Red Dwarfs Protect Their Planets*: Red dwarfs may protect their habitable planets better than the Sun protects the Earth.

June 20, 2009: Huge Stellar Nursery Found in Outer Galaxy*: It's more than ten times the size of the Orion Nebula.

February 18, 2009: Extrasolar Neptune-Pluto Analogue Discovered: A newfound pair of extrasolar planets may boost the planetary prospects of Pluto.

August 16, 2008: Milky Way Keeps Grip on Neighbor*: The Large Magellanic Cloud is here to stay.

July 12, 2008: Stellar Theft Sends Guilty Star Into a Spin: A white dwarf explains why Regulus spins so fast it's not round.

April 24, 2008: Will Mercury Hit Earth Someday?: The Sun's innermost planet may crash into Earth.

February 15, 2008: Meteorites from Mercury?*: Some rocks on Earth are probably from Mercury.

December 2007: Catching Andromeda's Light: The giant galaxy next door is a lot like ours.

June 19, 2007: New Distance to the Orion Nebula, Part Two*: Parallax confirms a new, shorter distance to the Orion Nebula.

May 14, 2007: Unveiling a Galactic Collision in Capricornus*: Two objects discovered during the nineteenth century are really colliding galaxies.

May 8, 2007: First Detection of Thorium in Another Galaxy*: Thorium in the Ursa Minor dwarf galaxy offers the first chance to measure another galaxy's age via radioactive dating.

April 6, 2007: The Stellar Origin of Copper*: The copper in pennies arose during the lives of stars like Rigel and Betelgeuse.

April 2007: The Blue Witch: The Witch Head Nebula shines by reflected glory from nearby Rigel.

March 14, 2007: The Widest Very Low Mass Binary*: Two faint red stars in Phoenix are traveling through space together--though separated by more than a hundred Sun-Pluto distances.

January 22, 2007: Malin 1: A Bizarre Galaxy Gets Slightly Less So*: Hubble reveals a normal disk of stars at the center of this giant low surface brightness galaxy.

January 15, 2007: New Distance to the Orion Nebula*: The Orion Nebula is closer than you thought.

December 18, 2006: A Primordial Galaxy in Cetus?*: A nearby dwarf galaxy may be a pristine building block of large galaxies like our own.

December 11, 2006: Is Pluto a Planet? This is a PDF file that presents arguments both for and against Pluto's planethood--please allow two minutes to download.

November 6, 2006: Red Dwarfs With Planets Have Low Metallicities: Three of the nearest red dwarf stars with planets all have less iron than the Sun.

October 30, 2006: Rainbow Whirlpools*: Two rainbow-colored images vividly show the differing distributions of the Whirlpool Galaxy's atomic and molecular hydrogen gas.

October 26, 2006: The First Cepheid Distance to NGC 55*: This galaxy may be orbiting another galaxy in the Sculptor group.

October 23, 2006: Stars Without Galaxies*: Most of the intergalactic stars in the Virgo cluster are old and metal-poor.

October 5, 2006: Pluto Question 2: How bright would the brightest planets look if they were as far as Pluto?

October 3, 2006: No Ocean on Neptune--Yet*: Neptune has no ocean, but it may develop one in 8 billion years.

September 26, 2006: Pluto Question: How bright would Pluto be if it were as close as Mars?

September 21, 2006: The Lives of Red Dwarf Stars*: The closer a red dwarf is to the Galactic plane, the more likely it is to sport magnetic activity.

September 6, 2006: The Pleiades' Lost Sister?*: An ultramassive white dwarf in Eridanus may have escaped from the Pleiades.

July 24, 2006: A Pulsating Red Giant's Bow Shock*: The Spitzer Space Telescope detects a bow shock around R Hydrae.

June 8, 2006: First Precise Distance to Shaula*: The second brightest star in Scorpius is a lot closer to Earth than astronomers had thought.

May 31, 2006: The First Cepheid Distance to Centaurus A*: The Hubble Space Telescope detects the first Cepheids ever seen in an elliptical galaxy--and measures its distance.

May 28, 2006: The First Binary Centaur*: The Hubble Space Telescope spots the first binary centaur ever seen.

April 19, 2006: Two New Galaxies Orbiting the Milky Way: Astronomers discover two satellites of our Galaxy in Boötes and Canes Venatici.

April 9, 2006: Black Holes in Quasars Spin Fast*: The fast spins make quasars emit much more light than they otherwise would.

March 10, 2006: A Solar Twin in the Big Dipper*: There's a star like the Sun in the Big Dipper.

January 31, 2006: The Horsehead Nebula is Rotating*: Astronomers give this famous nebula a spin.

January 29, 2006: Andromeda X: Andromeda's Newest Satellite Galaxy: It's the dimmest galaxy ever seen orbiting Andromeda.

January 19, 2006: Most Stars Are Single*: Two thirds of all star systems are single, like the Sun.

January 11, 2006: The Cosmic Origin of Carbon*: Most carbon on Earth came from stars that did not explode.

January 5, 2006: The Tenth Planet's First Anniversary: January 5 marks the date when the Sun's tenth planet was discovered.

January 3, 2006: Pulsar at the Galactic Center?*: It may be only one light-year from the Milky Way's central black hole.

December 21, 2005: The Three Moons of Pluto*: Astronomers determine the best orbits yet of Pluto's two new moons.

November 11, 2005: The First Interstellar Gas in a Globular Cluster?*: Astronomers find evidence for hydrogen gas between M15's many stars.

November 11, 2005: A Flare for Barnard's Star*: Just six light-years from the Sun, an old red star springs to life.

November 4, 2005: The First Direct Distance to Andromeda*: It agrees perfectly with less direct techniques.

September 12, 2005: A Giant Surprise*: Planet-bearing giant stars tend to be more metal-poor than other stars with planets.

September 2005: The Dumbbell Nebula's Harvest of Nitrogen: An expanding bubble enriches the Galaxy with nitrogen and may help life begin.

August 29, 2005: 100 Billion Brown Dwarfs*: Brown dwarfs may rival the number of all normal stars in our Galaxy.

August 4, 2005: A Solar Twin in Serpens?*: A far-off star may be the Sun's close cousin.

July 27, 2005: The Life and Times of Sirius B*: Sirius was once even brighter.

July/August 2005: Gould's Belt: Ring Around the Sky: Harboring some of the Milky Way's best-known features, Gould's belt lights the sky with superstars.

June 16, 2005: Charging Up the Universe*: When did the universe reionize itself? The Milky Way's oldest stars may hold the answer.

May 27, 2005: Extrasolar Comets*: Here's how to see a comet around another star.

April 19, 2005: The Outer Milky Way's Exotic Origin*: Did a galactic collision create the stars in our Galaxy's outer disk?

April 13, 2005: Andromeda's Vast Starry Disk*: M31 is a lot larger than it looks.

March 28, 2005: The Milky Way's Newest Satellite*: Astronomers spot the dimmest galaxy ever seen--orbiting the Milky Way.

March 2005: Descendants of the Dipper: Heart of the best-known star pattern, the Ursa Major moving group probes the behavior of young stars and the chemical evolution of the Galaxy.

February 18, 2005: The First Dark Galaxy?*: Astronomers may have discovered a galaxy without stars.

February 17, 2005: Pinpointing a Stellar Neighbor*: A feisty red dwarf in Antlia becomes the Sun's 28th nearest neighbor.

February 11, 2005: Do Brown Dwarfs Pulsate?*: The least massive stars may resemble Cepheids.

January 27, 2005: The Galaxy's Youngest Globular Cluster?*: Whiting 1 may be as young as the Sun.

January 19, 2005: The Age of Procyon*: The bright nearby star Procyon is 1.7 billion years old.

January 19, 2005: The Lion's Pumpkin-Shaped Heart: Rapid rotation flattens Regulus.

January 7, 2005: The Distance to a Stellar Youngster*: Astronomers pinpoint the parallax of T Tauri.

January 6, 2005: The Milky Way's First Light*: In its youngest days, our Galaxy may have favored producing stars like Vega and Regulus.

December 10, 2004: A New Star in the Neighborhood*: Astronomers have found a dim red star in the Sun's backyard.

November 15, 2004: Beta Centauri Weighs In*: Astronomers have measured the mass and distance of the eleventh brightest star in the night.

March 2004: M67: The Ultimate Survivor: This ancient star cluster has cheated death for some 4 billion years.

December 2003: The Black Cloud: A frigid blob of gas and dust hovers nearby, possibly foreshadowing a stellar birth.

September 2003: Fluorine: An Element-ary Mystery: The best-known ingredient in toothpaste has stellar origins that are anything but ordinary.

July 2002: The Brightest Red Dwarf: The brightest red dwarf resides in an obscure constellation, catalogued by an equally obscure pioneer in astronomy.

January 27, 2001: Red, Willing, and Able: Far from being desolate backwaters, red dwarfs may harbor an abundance of alien life.

December 13, 1997: 51 Pegasi: Planet, Not Pulsation*: 51 Pegasi's planet is real.

October 1997: The First Cepheid: The Cepheid story did not start with their namesake but with the largely overlooked star Eta Aquilae.

May 3, 1997: Scorpius Star is Twinned with Sun*: If you want to boost your chances of finding extraterrestrial intelligence, point your telescope at a star in the constellation of Scorpius.

April 1995: California Tornado Risk: Tornadoes hit California, too.

July 1993: The South American Appalachians: The Appalachians may be the remnant of an immense mountain range that once extended into Argentina.

January 30, 1993: Hopes Fade in Hunt for Planet X*: A newly determined mass for Neptune dooms Planet X, the hypothetical massive planet beyond Pluto.

December 18/25, 1992: How Lithium Strips Brown Dwarfs of Their Red Disguise*: Here's how to tell a red dwarf from a brown dwarf.

October 24, 1992: Why Intelligent Life Needs Giant Planets*: Without Jupiter and Saturn, intelligent life might never have arisen on Earth.

June 20, 1992: Nitrogen in Pluto's Atmosphere*: Pluto is the only planet apart from Earth with an atmosphere consisting mostly of nitrogen.

KEN CROSWELL'S ARTICLES BY SUBJECT

THE SOLAR SYSTEM

			THE SUN

An Elemental Problem with the Sun: For two decades astronomers have been arguing over exactly how much carbon, nitrogen, and especially oxygen the Sun has--with implications for the entire universe.

Neutrinos Hint the Sun Has More Carbon and Nitrogen than Previously Thought*: Figuring out our star’s makeup is crucial for understanding the entire universe.

Can the Sun's Siblings Be Found?*: The Milky Way's spiral arms may have scattered the Sun's siblings hither and yon.

Neutrinos from Sun's Main Nuclear Reaction Detected: Numbers agree with the standard solar model.

			MERCURY

Meteorites from Mercury?: Some rocks on Earth are probably from Mercury.

Will Mercury Hit Earth Someday?: The Sun's innermost planet may crash into Earth.

Good News, Earthlings: The Planet Mercury Probably Won't Kill Us: Mercury may crash into Venus, but Earth is probably safe, if a new study is right.

			VENUS

Venus: Doomed From the Start? The nearest planet probably never had oceans or life.

			EARTH

Sulfur Was Key to the First Water on Earth*: The find suggests all rocky planets get wet soon after birth, boosting the chances for life.

California Tornado Risk: Tornadoes hit California, too.

The South American Appalachians: The Appalachians may be the remnant of an immense mountain range that once extended into Argentina.

One Black Hole Won't Ruin Your Day: If a primordial black hole hits Earth, you'll probably feel just fine.

			MARS

Marsquakes Shake Up Views of the Red Planet's Deep Interior: The InSight spacecraft's seismometer sizes up the Martian crust, mantle, and core.

Supervolcanoes Spotted on Mars: Colossal eruptions rocked the red planet's youth.

Oldest Minerals From Mars Found on Earth: New Martian meteorite sheds light on the red planet's earliest years.

A Dash of Hydrogen and Methane Could Have Kept Mars Warm*: New calculations may solve the mystery of how ancient Mars got warm enough for rivers to flow.

An Ambitious New Mission Seeks the Origin of the Moons of Mars: Are Phobos and Deimos Captured Asteroids, or Did They Form After a Large Object Hit the Red Planet?

			JUPITER AND SATURN

Why Intelligent Life Needs Giant Planets*: Without Jupiter and Saturn, intelligent life might never have arisen on Earth.

Was Jupiter Born Beyond the Current Orbits of Neptune and Pluto? Conventional theory says Jupiter was born where it is now. Two groups of researchers working independently have proposed an intriguing alternative.

Why Jupiter's Big Moons Outnumber Saturn's: Jupiter 4, Saturn 1. Why?

Is Jupiter Eating Its Own Heart?*: Some gas giant planets may have destroyed their cores.

A Shadowy Birthplace May Explain Jupiter's Strange Chemistry: A frigid planetary nursery could account for the gas giant’s peculiar atmospheric composition.

Gentle or Jumping? The Varied Lives of Hot Jupiters*: A newborn star's iron abundance foretells whether its gas giants face a violent future.

Saturn Is Shaking Its Rings*: Oscillations inside the giant planet perturb its rings, promising new clues to the nature of its enormous interior.

Saturn Has a Fuzzy Core, Spread Over More Than Half the Planet's Diameter*: A wave in one of the rings reveals the size and composition of the planet's core.

Tides Control the Geysers of Enceladus: Their strength depends on the moon's distance from Saturn.

Saturn's First Trojan Asteroid Has Finally Been Discovered*: All four giant planets now have known asteroids sharing their orbits.

			URANUS

Uranus and Neptune: The Neglected Planets [cover story]: Decades after a lone spacecraft flew by, the solar system's ice giants and their many moons still guard plenty of secrets.

Seeking Answers, Planetary Scientists Plot a Return to the Nearest Ice Giant: Uranus beckons.

Uranus Might Have Two Dark Moons We've Never Seen Before*: Newly detected wavy patterns in two of Uranus's rings suggest the possible presence of two small, unseen satellites.

Some of Uranus's Small Moons Are Doomed to Collide*: The first measurement of the mass of a small moon of Uranus suggests it will be obliterated after smashing into another satellite in the next million years.

			NEPTUNE

Uranus and Neptune: The Neglected Planets [cover story]: Decades after a lone spacecraft flew by, the solar system's ice giants and their many moons still guard plenty of secrets.

New Moon Over Neptune: Hubble spots a new satellite around the distant giant planet.

No Ocean on Neptune--Yet*: Neptune has no ocean, but it may develop one in 8 billion years.

			PLUTO

Nitrogen in Pluto's Atmosphere*: Pluto is the only planet apart from Earth with an atmosphere consisting mostly of nitrogen.

The Three Moons of Pluto*: Astronomers determine the best orbits yet of Pluto's two new moons.

Pluto Question: How bright would Pluto be if it were as close as Mars?

Pluto Question 2: How bright would the brightest planets look if they were as far as Pluto?

Ninth Rock From the Sun: It's time for a new and improved definition of "planet"--one that restores Pluto to its former glory.

Pluto's Moons Offer Hints of Alien Worlds*: The distant satellites may show how planets orbit double stars.

Pluto's Revenge: Hubble Finds a Fifth Moon: Discovery boosts Pluto's planetary cred.

Wanted: New Worlds Beyond Pluto: Scientists work to keep an intrepid spacecraft busy.

Captain Kirk Is Defeated at Pluto: William Shatner loses his battle to name a distant moon Vulcan.

Air Apparent: Pluto's Eternal Atmosphere: New observations suggest the small world's air never vanishes.

			ERIS

The Tenth Planet's First Anniversary: January 5 marks the date when the Sun's tenth planet was discovered.

			PLANET X

Hopes Fade in Hunt for Planet X*: A newly determined mass for Neptune dooms Planet X, the hypothetical massive planet beyond Pluto.

			CENTAURS

The First Binary Centaur*: The Hubble Space Telescope spots the first binary centaur ever seen.

			EDGEWORTH-KUIPER BELT

Who First Described the Comet Belt Just Beyond Neptune? It's time the so-called Kuiper Belt was finally rebranded.

Pluto's Egg-Shaped Neighbor Haumea Has a Ring No One Expected: It's the farthest ring ever seen in our solar system.

			METEORS

Origins of a Mighty Meteor Shower [cover story]: How does a space rock make such a stunning display of shooting stars?

The Return of a Great Nineteenth-Century Meteor Shower*: Long thought nearly extinct, the Andromedid meteor shower staged a surprise outburst last December—and may return in 2018 and 2023.

			INTERSTELLAR ASTEROIDS AND COMETS

Astronomers Race to Learn from First Interstellar Asteroid Ever Seen: For the first time, we've seen an asteroid from another solar system visit our own.

			THE HELIOPAUSE

Voyager Still Breaking Barriers Decades After Launch: As Voyagers 1 and 2 continue their epic journeys through interstellar space, they're resolving past controversies and even helping to spark a new one: the true shape of the heliosphere.

THE STARS

Most Stars Are Single*: Two thirds of all star systems are single, like the Sun.

Astronomers Uncover New Way to Measure the Speed of Stars: New observations now allow the seemingly impossible: determining how quickly some stars move toward us without measuring their Doppler shifts.

Who Really Discovered Stellar Proper Motion? Contrary to many books and articles, the answer isn't who you think.

Record-Breaking Double Star May Be Cannibalising Itself*: An extreme binary “eclipses” Epsilon Aurigae by having an orbital period more than twice as long.

			INTERSTELLAR MEDIUM

The Black Cloud: A frigid blob of gas and dust hovers nearby, possibly foreshadowing a stellar birth.

The Star That Never Was*: Stardom is just a pipe dream.

The Blue Witch: The Witch Head Nebula shines by reflected glory from nearby Rigel.

The Horsehead Nebula is Rotating*: Astronomers give this famous nebula a spin.

New Distance to the Orion Nebula*: The Orion Nebula is closer than you thought.

New Distance to the Orion Nebula, Part Two*: Parallax confirms a new, shorter distance to the Orion Nebula.

Huge Stellar Nursery Found in Outer Galaxy*: It's more than ten times the size of the Orion Nebula.

Giant Molecular Cloud in Solar Neighborhood: The California Nebula has a dark secret.

Prodigal Gas Cloud Was Born in Milky Way and Is Crashing Back in*: Astronomers pinpoint the birthplace of a mysterious cloud in space.

Space is the Place for Impossible Molecules: Molecules containing noble gases don't form naturally on Earth. But they do in the interstellar medium.

			STAR FORMATION

The Story of T Tauri: An infant star in Taurus helped reveal a truth once thought radical: the universe still makes new stars.

The Milky Way May Be Spawning Many More Stars than Astronomers Had Thought: Gamma rays reveal the Galaxy's star-making power.

Poof! Planet-Forming Disk Vanishes Into Thin Air: The same cosmic mystery may have occurred in our solar system.

Baby Star Found on Earth's Doorstep*: The nearest pre-main-sequence star ever found may sport glowing planets.

The Distance to a Stellar Youngster*: Astronomers pinpoint the parallax of T Tauri.

Nearest Newborn Stars Discovered: A double star just 20 light-years from Earth is surprisingly young, offering bright prospects for planet hunters.

Most Stars May Have Much More Time to Form Planets Than Previously Thought*: Planet-making disks may survive around many young stars for 5 to 10 million years.

			OB STARS

Gould's Belt: Ring Around the Sky: Harboring some of the Milky Way's best-known features, Gould's belt lights the sky with superstars.

The Fastest Spinning Normal Star*: It spins 300 times faster than the Sun.

Beta Centauri Weighs In*: Astronomers have measured the mass and distance of the eleventh brightest star in the night.

The Lion's Pumpkin-Shaped Heart: Rapid rotation flattens Regulus.

Stellar Theft Sends Guilty Star Into a Spin: A white dwarf explains why Regulus spins so fast it's not round.

First Precise Distance to Shaula*: The second brightest star in Scorpius is a lot closer to Earth than astronomers had thought.

Runaway Stars May Create the Mysterious Ultraviolet Glow Around Some Galaxies*: The bright, young stars are located in regions where gas is too tenuous for new stars to form.

			A-TYPE MAIN-SEQUENCE STARS

The Life and Times of Sirius B*: Sirius was once even brighter.

Older Vega Is Mature Enough for Primitive Life*: The star of Contact is older than had been thought.

Fomalhaut Is Triple*: The bright star has a red dwarf companion--2.5 light-years away.

			FGK MAIN-SEQUENCE STARS

Proxima Centauri Really Does Orbit Its Two Bright Neighbours*: After a century of speculation, astronomers confirm that Proxima Centauri revolves around Alpha Centauri A and B.

Another Earth 12 Light-Years Away?: Five planets may orbit Tau Ceti.

The Age of Procyon*: The bright nearby star Procyon is 1.7 billion years old.

Scorpius Star is Twinned with Sun*: If you want to boost your chances of finding extraterrestrial intelligence, point your telescope at a star in the constellation of Scorpius.

A Solar Twin in Serpens?*: A far-off star may be the Sun's close cousin.

A Solar Twin in the Big Dipper*: There's a star like the Sun in the Big Dipper.

Double Star Hosts Ancient World*: It's 2 billion years older than Earth.

			RED DWARFS

Red, Willing, and Able: Far from being desolate backwaters, red dwarfs may harbor an abundance of alien life.

The Story of Wolf 359: A little red sun in Leo was once the least luminous star known.

A Star From Another Galaxy*: One of our nearest stellar neighbors--Kapteyn's Star, just 13 light-years from Earth--probably originated in another galaxy.

How Red Dwarfs Protect Their Planets*: Red dwarfs may protect their habitable planets better than the Sun protects the Earth.

The Brightest Red Dwarf: The brightest red dwarf resides in an obscure constellation, catalogued by an equally obscure pioneer in astronomy.

A Flare for Barnard's Star*: Just six light-years from the Sun, an old red star springs to life.

A New Star in the Neighborhood*: Astronomers have found a dim red star in the Sun's backyard.

Pinpointing a Stellar Neighbor*: A feisty red dwarf in Antlia becomes the Sun's 28th nearest neighbor.

The Lives of Red Dwarf Stars*: The closer a red dwarf is to the Galactic plane, the more likely it is to sport magnetic activity.

Red Dwarfs With Planets Have Low Metallicities: Three of the nearest red dwarf stars with planets all have less iron than the Sun.

The Widest Very Low Mass Binary*: Two faint red stars in Phoenix are traveling through space together--though separated by more than a hundred Sun-Pluto distances.

Planets "Sing" in Three-Part Harmony*: Astronomers discover the first three-planet resonance--around a star just 15 light-years away.

Tides Turn Some "Habitable" Planets Into Hellish Hothouses*: Planets close to small red dwarfs may be "tidal Venuses."

Nearest Newborn Stars Discovered: A double star just 20 light-years from Earth is surprisingly young, offering bright prospects for planet hunters.

A Star at the Edge of Eternity: A Saturn-sized star just 40 light-years away will outlive nearly all of its peers.

Proxima's Unprecedented Passage: When Stars Align: The Sun's closest stellar neighbor will soon reveal its mass--and possibly its planets--when it passes in front of a distant star.

Proxima Centauri Really Does Orbit Its Two Bright Neighbours*: After a century of speculation, astronomers confirm that Proxima Centauri revolves around Alpha Centauri A and B.

Dwarf Carbon Stars: Stars that shouldn't even exist may soon offer new clues to the ancient universe and the Galaxy's birth.

A Brightness Gap Exposes the Inner Lives of Red Dwarf Stars: Red dwarfs can pulsate.

			BROWN DWARFS

Here's How Cool a Star Can Be and Still Achieve Lasting Success*: The motions of nearby stars reveal the boundary between red dwarfs and brown dwarfs.

Water Clouds Tentatively Detected Just 7 Light-Years from Earth*: They're the first water clouds seen beyond our solar system.

Nearby Brown Dwarf Has Partly Cloudy Skies: Clues emerge to weather patterns on "hot Jupiters".

How Many Stars Never Make the Big Time?*: Search for brown dwarfs reveals the odds of stellar success.

Newly Found Brown Dwarf Is Ultracool*: It's room temperature.

"Dark Sun" Is One of Our Nearest Neighbors: A newfound star less than 10 light-years from Earth appears to be the closest brown dwarf ever detected.

100 Billion Brown Dwarfs*: Brown dwarfs may rival the number of all normal stars in our Galaxy.

Do Brown Dwarfs Pulsate?*: The least massive stars may resemble Cepheids.

How Lithium Strips Brown Dwarfs of Their Red Disguise*: Here's how to tell a red dwarf from a brown dwarf.

			GIANTS AND SUPERGIANTS

When Red Giants Were Young: One hundred years ago astronomers thought large, cool stars were destined to become stars like the Sun.

The First Cepheid: The Cepheid story did not start with their namesake but with the largely overlooked star Eta Aquilae.

The North Star is Much Heavier Than Previously Thought*: Polaris is nearly 50 percent more massive than an earlier study found.

Giant Stars Bare Their Whirling Hearts: Their cores spins much faster than their surfaces.

A Giant Surprise*: Planet-bearing giant stars tend to be more metal-poor than other stars with planets.

A Pulsating Red Giant's Bow Shock*: The Spitzer Space Telescope detects a bow shock around R Hydrae.

A New Image Captures Enormous Gas Rings Encircling an Aging Red Star*: The star is losing mass as it transforms into a white dwarf star.

			PLANETARY NEBULAE

The Dumbbell Nebula's Harvest of Nitrogen: An expanding bubble enriches the Galaxy with nitrogen and may help life begin.

			WHITE DWARFS

The First White Dwarf [cover story]: The road to discovering a new type of star was long and winding.

The Fastest Stars Escaping the Galaxy: Exploding white dwarfs can hurl their companions away at record speed, dooming them to roam intergalactic space for all eternity.

Can Dying Stars Support Life?: White dwarfs may have habitable planets.

"Cold" Hydrogen Molecules Found on Hot Stars*: Surprise discovery may probe the conditions on white dwarfs.

The Life and Times of Sirius B*: Sirius was once even brighter.

The Pleiades' Lost Sister?*: An ultramassive white dwarf in Eridanus may have escaped from the Pleiades.

"Earth-Mars" Collision May Have Hit Alien Solar System*: Did something whack a dim star's planet--and create a new moon?

			SUPERNOVAE

A Massive Star Dies Without a Bang: Evidence emerges that not all red supergiants explode, raising the possibility that Betelgeuse will never go supernova.

The Milky Way Supernova You've Never Heard Of*: A newly measured distance to stellar debris in the northern sky ties it more firmly to an explosion observers saw in 1181.

First Noble Gas Molecules Found in Space: Argon hydride spotted in remnant of exploded star.

A Gargantuan Supernova Remnant Looks 40 Times Bigger than the Full Moon*: From Earth's perspective, it's the largest cloud of debris ever seen from an exploded star.

			NEUTRON STARS AND PULSARS

The Heaviest Neutron Star on Record Has 2.35 Times the Mass of the Sun*: The discovery helps refine the dividing line between neutron stars and black holes.

Strange Cosmic Radio Burst Pinned Down to Giant Stellar Nursery*: A young neutron star is probably the source of a strange repeating signal previously tracked to a dwarf galaxy 2.4 billion light-years away.

Pulsar Will Put the Test to General Relativity: Trio of dead stars will subject Einstein's strong equivalence principle to its most stringest test ever.

Pulsar at the Galactic Center?*: It may be only one light-year from the Milky Way's central black hole.

			BLACK HOLES

Gaia Begins a Black Hole Revolution: Most black holes are quiet, and the Gaia spacecraft is starting to find them.

Famous Black Hole Confirmed After Forty Years*: The first parallax to Cygnus X-1 reveals that it must contain a black hole.

The Fate of the First Black Hole*: The black hole of Cygnus X-1 will likely separate from its long-suffering partner.

One Black Hole Won't Ruin Your Day: If a primordial black hole hits Earth, you'll probably feel just fine.

The Nearest Midsized Black Hole Might Instead Be a Horde of Lightweights*: A claim of an intermediate-mass black hole in a Milky Way star cluster comes under scrutiny.

			NOVAE

The Little Stars That Can: Surprising new observations reveal novae forging a lightweight metal whose price keeps going up and up.

Dancing Stars Turn on the Red Light*: Two stars merge and trigger a rare type of nova.

Cannibal Stars Explode Violently – as Predicted by Darwin’s Son*: Big star eats little star.

Mating Stars Hide Their Modesty Behind a Thick Veil of Dust: A torus of thick dust surrounds two stars that recently merged into one.

Double Star May Light Up the Sky as Rare Red Nova in Six Years*: New observations of KIC 9832227 show it's on track to become a rare “red nova.”

The Number of Milky Way Nova Explosions Per Year Has Been Pinned Down*: Every year about four dozen of these stellar eruptions occur in our Galaxy.

			STAR CLUSTERS

The Closest Star Cluster to Earth is in Its Death Throes*: Stars in the Hyades cluster are dashing past one another so fast it will disintegrate in only 30 million years.

The Milky Way's Dimmest Star Cluster*: Segue 3 ekes out just 90 Suns' worth of light.

Can the Sun's Siblings Be Found?*: The Milky Way's spiral arms may have scattered the Sun's siblings hither and yon.

Astronomers Measure Precise Distance to Controversial Star Cluster: But a top scientist blasts the result.

The Pleiades' Lost Sister?*: An ultramassive white dwarf in Eridanus may have escaped from the Pleiades.

M67: The Ultimate Survivor: This ancient star cluster has cheated death for some 4 billion years.

The Nearest Midsized Black Hole Might Instead Be a Horde of Lightweights*: A claim of an intermediate-mass black hole in a Milky Way star cluster comes under scrutiny.

The First Interstellar Gas in a Globular Cluster?*: Astronomers find evidence for hydrogen gas between M15's many stars.

The Galaxy's Youngest Globular Cluster?*: Whiting 1 may be as young as the Sun.

			MOVING GROUPS

Baby Star Found on Earth's Doorstep*: The nearest pre-main-sequence star ever found may sport glowing planets.

Descendants of the Dipper: Heart of the best-known star pattern, the Ursa Major moving group probes the behavior of young stars and the chemical evolution of the Galaxy.

			NUCLEOSYNTHESIS

Tracing Gold's Cosmic Origin Story: Astronomers thought they had finally figured out where the gold, platinum, and other heavy elements in the universe came from. In light of recent results, they’re not so sure.

The Cosmic Origin of Carbon*: Most carbon on Earth came from stars that did not explode.

The Dumbbell Nebula's Harvest of Nitrogen: An expanding bubble enriches the Galaxy with nitrogen and may help life begin.

Fluorine: An Element-ary Mystery: The best-known ingredient in toothpaste has stellar origins that are anything but ordinary.

First Noble Gas Molecules Found in Space: Argon hydride spotted in remnant of exploded star.

The Stellar Origin of Copper*: The copper in pennies arose during the lives of stars like Rigel and Betelgeuse.

			EXTRASOLAR PLANETS

51 Pegasi: Planet, Not Pulsation*: 51 Pegasi's planet is real.

Another Earth 12 Light-Years Away?: Five planets may orbit Tau Ceti.

Extrasolar Neptune-Pluto Analogue Discovered: A newfound pair of extrasolar planets may boost the planetary prospects of Pluto.

Hot World Breaks Record*: It's the hottest planet yet.

Far-out Earths Could Support Alien Life*: A life-bearing planet can exist far from its star--if its air abounds with hydrogen.

Can Dying Stars Support Life?: White dwarfs may have habitable planets.

A Giant Surprise*: Planet-bearing giant stars tend to be more metal-poor than other stars with planets.

Extrasolar Comets*: Here's how to see a comet around another star.

Red Dwarfs With Planets Have Low Metallicities: Three of the nearest red dwarf stars with planets all have less iron than the Sun.

Wrong-Way Planets: Many extrasolar planets orbit their stars against the grain.

Tilting Stars May Explain Backward Planets*: Stellar flips may explain some wrong-way planets.

Stars Steal Their Planet's Moons: Hot Jupiters may be moonless.

Planets "Sing" in Three-Part Harmony*: Astronomers discover the first three-planet resonance--around a star just 15 light-years away.

"Earth-Mars" Collision May Have Hit Alien Solar System*: Did something whack a dim star's planet--and create a new moon?

Some Planets Are Alien Invaders*: Billions of stars in our Galaxy may have captured their most distant worlds.

Double Star Hosts Ancient World*: It's 2 billion years older than Earth.

Pluto's Moons Offer Hints of Alien Worlds*: The distant satellites may show how planets orbit double stars.

Hot Jupiters Are Loners: Gas giants orbiting next to their suns have no close planetary neighbors.

Gentle or Jumping? The Varied Lives of Hot Jupiters*: A newborn star's iron abundance foretells whether its gas giants face a violent future.

Diamond Planets Get Even More Precious: Carbon planets are a lot rarer than had been thought.

Kepler Finds the First Tilted Solar System: Two planets circle their aging sun at a 45-degree angle.

Gang of Gas Giants May Have Tilted Distant Solar System*: Astronomers pin down the likely culprit behind the first tilted solar system ever found.

Most Planets on Tilted Orbits Pass Over the Poles of Their Suns*: The surprising discovery may reveal how misaligned worlds arise.

How Hot Jupiters May Get Their Weirdly Tight Orbits*: Stars and neighboring planets can fling giant worlds toward their suns.

			EXTRATERRESTRIAL LIFE

Far-out Earths Could Support Alien Life*: A life-bearing planet can exist far from its star--if its air abounds with hydrogen.

Can Dying Stars Support Life?: White dwarfs may have habitable planets.

No Home For Life in the Galactic Outer Suburbs*: If the Sun had been born near the edge of the Milky Way, we probably wouldn't exist.

Scorpius Star is Twinned with Sun*: If you want to boost your chances of finding extraterrestrial intelligence, point your telescope at a star in the constellation of Scorpius.

A Solar Twin in Serpens?*: A far-off star may be the Sun's close cousin.

A Solar Twin in the Big Dipper*: There's a star like the Sun in the Big Dipper.

Red, Willing, and Able: Far from being desolate backwaters, red dwarfs may harbor an abundance of alien life.

How Red Dwarfs Protect Their Planets*: Red dwarfs may protect their habitable planets better than the Sun protects the Earth.

Tides Turn Some "Habitable" Planets Into Hellish Hothouses*: Planets close to small red dwarfs may be "tidal Venuses."

"Goldilocks Stars" May Pose Problems for Any Nearby Habitable Planets*: Far-ultraviolet radiation from orange dwarfs could endanger planetary atmospheres.

THE GALAXIES

Galaxies Defy Astronomers' Expectations: Galaxies formed stars differently in the early universe.

Little Galaxy's Own Stars Cast 95 Per Cent of Its Oxygen Away*: It's not easy being a little galaxy.

			THE MILKY WAY

Star Struck: Astronomers turn their telescopes to the unbounded beauty of the Milky Way.

Dawn of the Milky Way: New observations are unveiling the earliest years of our Galaxy.

Astronomers Are Redrawing Our Corner of the Milky Way: Remarkable new observations are revealing the starry landscape of our Galactic neighborhood and our place within it.

Mapping the Milky Way [cover story]: Recent years have seen tremendous strides in unraveling the Galaxy's spiral arms, and the next decade promises the best maps ever made of our celestial home.

The Mighty Milky Way: Our Galaxy is far bigger, brighter, and more massive than most others.

The Cepheus Spur: A newly named feature in our Galaxy drapes distant luminaries across the northern sky from Cepheus and Camelopardalis to Auriga, Gemini, Taurus, and Orion.

The Milky Way's Most Massive Star Cluster May Have Eaten a Smaller Cluster: Observations of newfound stars suggest how the gathering of stars at the Galaxy's core grew so big.

Astronomers Have Found the Edge of the Milky Way*: Our Galaxy's total diameter is a whopping 1.9 million light-years.

Galaxy Grande: Milky Way May Be More Massive Than Thought*: Hubble observations of a speedy galaxy weigh on the Milky Way and indicate that our Galaxy is at least a trillion times as massive as the Sun.

Speedy Star Points to More Massive Milky Way*: The fastest halo star ever seen may boost estimates of our Galaxy's mass.

Clocking the Hot Gas Gushing from the Milky Way's Core*: New observations of the Fermi bubbles indicate the Galaxy's core erupted 2.5 to 4 million years ago.

Far Out: The Most Distant Star in the Milky Way: A star 890,000 light-years away patrols our Galactic frontier.

A Stellar Discovery on the Far Side: Five remarkable stars on the other side of our Galaxy promise new insight into the outer reaches of our home turf.

The Outer Milky Way's Exotic Origin*: Did a galactic collision create the stars in our Galaxy's outer disk?

The Milky Way's Oldest and Wisest Stars: An astronomer invents a new technique to trace the origins of our Galaxy.

Charging Up the Universe*: When did the universe reionize itself? The Milky Way's oldest stars may hold the answer.

The Milky Way's First Light*: In its youngest days, our Galaxy may have favored producing stars like Vega and Regulus.

Pulsar at the Galactic Center?*: It may be only one light-year from the Milky Way's central black hole.

Danger: Black Hole Dead Ahead!: What may be a gas cloud is hurtling toward the Galaxy's biggest black hole.

Elderly Couple Kicked Out of the Galaxy: Astronomers find the first old stars escaping from the Milky Way.

The Milky Way's Central Black Hole May Have Turned Nearby Red Giant Stars Blue: A powerful blast from the supermassive black hole may explain a lack of large, red stars there.

Here's the Best Timeline Yet for the Milky Way's Big Events: Our Galaxy formed its original disk 2 billion years before its stellar halo.

A Protogalaxy in the Milky Way May Be Our Galaxy's Original Nucleus*: It's the kernel around which the Milky Way first formed.

			THE MAGELLANIC CLOUDS

Star Performers: The Magellanic Clouds: Two intrepid galaxies dash past the Milky Way--and dazzle astronomers.

Shredded Galaxy Is Disintegrating Before Our Eyes After Smash-Up*: After collision with a neighbouring galaxy, the Small Magellanic Cloud may lose its ability to spawn new stars.

A Tail of Two Galaxies*: A dual origin for the Magellanic Stream?

Busted! Nearby Galaxy Is a Stellar Thief*: The Large Magellanic Cloud snatched stars from its long-time companion.

Milky Way's Baby Brother Caught Copying Its Star-Shredding Habit*: The Large Magellanic Cloud is tearing apart a star cluster it may have stolen from another galaxy.

Star Birth Sparked at the Galaxy's Edge: Gas from another galaxy is hitting our own, triggering the birth of bright new stars and adding fresh luster to the Milky Way.

Hubble Finds Vast Reservoir of Gas Near the Milky Way: The Magellanic Stream may solve our Galaxy's impending gas shortage.

Milky Way Keeps Grip on Neighbor*: The Large Magellanic Cloud is here to stay.

Galaxy Smash-Up Revealed Next Door: The Small Magellanic Cloud suffered a big collision 7.5 billion years ago.

We Found Our Galactic Twin 180 Million Light-Years Away*: A galactic trio looks remarkably like the Milky Way and its two brightest companions, the Magellanic Clouds.

When the Magellanic Clouds Cozy Up to Each Other, Stars Are Born: Five synchronized peaks of star formation reveal the galaxies' most intimate encounters.

			OTHER MILKY WAY SATELLITES

The Milky Way Makes Little Galaxies Bloom, Then Snuffs Them Out*: Dwarf spheroidal galaxies light up with newborn stars when first approaching our Galaxy.

The Milky Way's Secret Companion?*: A large satellite galaxy may be lurking next to ours, hidden from sight.

Two New Galaxies Orbiting the Milky Way: Astronomers discover two satellites of our Galaxy in Boötes and Canes Venatici.

The Milky Way's Newest Satellite*: Astronomers spot the dimmest galaxy ever seen--orbiting the Milky Way.

First Detection of Thorium in Another Galaxy*: Thorium in the Ursa Minor dwarf galaxy offers the first chance to measure another galaxy's age via radioactive dating.

Never-Before-Seen Galaxy Spotted Orbiting the Milky Way*: The Crater 2 dwarf galaxy is our Galaxy's fourth largest satellite.

Torn-Apart Galaxy May Be Exacting Revenge on the Milky Way*: The Sagittarius dwarf was massive enough to warp the galaxy that's tearing it apart.

Kamikaze Galaxy Explodes After Diving Into the Milky Way*: The Hercules dwarf has the most elliptical orbit ever seen for a Milky Way satellite galaxy.

Super-Dim Galaxy May Be One of Hundreds Orbiting the Milky Way*: What may be the least luminous galaxy ever seen suggests our Galaxy has hundreds of equally dim satellites.

			THE ANDROMEDA GALAXY

The Drama Next Door: The Andromeda Galaxy is a giant spiral like the Milky Way but has had a surprisingly different, and tumultuous, past.

Catching Andromeda's Light: The giant galaxy next door is a lot like ours.

Starburst in Andromeda*: The giant Andromeda Galaxy owes a bit of its beauty to a galactic encounter.

The First Direct Distance to Andromeda*: It agrees perfectly with less direct techniques.

Andromeda's Vast Starry Disk*: M31 is a lot larger than it looks.

			ANDROMEDA SATELLITES

Andromeda X: Andromeda's Newest Satellite Galaxy: It's the dimmest galaxy ever seen orbiting Andromeda.

			OTHER LOCAL GROUP GALAXIES

A Primordial Galaxy in Cetus?*: A nearby dwarf galaxy may be a pristine building block of large galaxies like our own.

The Galaxy Collision Next Door*: Two dwarf galaxies may have smashed together in our Local Group, sparking the nearest "starburst."

			THE NGC 3109 ASSOCIATION

Nearby Primitive Galaxies Offer a Window into the Early Universe: Galaxies just beyond the Local Group illuminate the nature of the first stars.

			THE SCULPTOR GROUP

Nearby Galaxy May Be Victim of Dark Matter Hit-and-Run: A dark subhalo may have punched a hole in spiral galaxy NGC 247.

The First Cepheid Distance to NGC 55*: This galaxy may be orbiting another galaxy in the Sculptor group.

			THE M81 GROUP

Nearby Galaxy Harbors Rarest Type of Black Hole: M82's black hole is 400 times as massive as the Sun.

Hyperactive Galaxy Could Run Out of Gas in Just 8 Million Years*: Nearby "starburst" galaxy is using up and blowing out far more gas than it takes it, astronomers warn.

			THE CENTAURUS GROUP

The First Cepheid Distance to Centaurus A*: The Hubble Space Telescope detects the first Cepheids ever seen in an elliptical galaxy--and measures its distance.

			THE WHIRLPOOL GALAXY

Rainbow Whirlpools*: Two rainbow-colored images vividly show the differing distributions of the Whirlpool Galaxy's atomic and molecular hydrogen gas.

			THE VIRGO CLUSTER

Found: The Fastest Approaching Object in the Universe: It has a record-setting blueshift of 1,026 kilometers per second.

The First Dark Galaxy?*: Astronomers may have discovered a galaxy without stars.

Stars Without Galaxies*: Most of the intergalactic stars in the Virgo cluster are old and metal-poor.

			THE FORNAX CLUSTER

Spiralling Arms Help Spread Oxygen Around for Future Planets*: The spiral arms of a galaxy named NGC 1365 contain 60 percent more oxygen than the space between, the most extreme variation ever seen.

			OTHER GALAXY CLUSTERS

The "USS Jellyfish" Emits Strange Radio Waves from a Distant Galaxy Cluster: Spanning 1.2 million light-years, the entity broadcasts a never-before-seen pattern of radio waves.

			SUPERCLUSTERS AND VOIDS

The Void Next Door [cover story]: An enormous region of darkness starts on our doorstep, giving astronomers their best chance to probe one of these gigantic cosmic structures.

How To Find Your Way Home from Deep Space: Astronomers unfurl a map more than a billion light-years across.

			SPIRAL GALAXIES

Spendthrift Spirals: The great spiral galaxies that adorn the modern universe are running out of gas and may someday lose their beautiful shapes.

High-Speed Collisions Prevent Star Formation in Galactic Bars: Simulations of the stunning barred spiral galaxy NGC 1300 explain why its bar fails to sparkle with newborn stars.

Hubble Spots the Farthest Spiral Galaxy Ever Seen: It flaunted its spiral arms just 3 billion years after the big bang.

Do Spiral Galaxies Form from the Inside Out?*: Distant spiral sheds light on galaxy formation.

Super Spiral Galaxies Amaze Astronomers*: A new breed of giants raises questions about how the biggest galaxies arise.

Runaway Stars May Create the Mysterious Ultraviolet Glow Around Some Galaxies*: The bright, young stars are located in regions where gas is too tenuous for new stars to form.

			DWARF GALAXIES

How Tiny "Dead" Galaxies Get Their Groove Back and Make Stars Again*: Gas falling into a dwarf galaxy must fight the galaxy's own stars before making new ones.

			LOW SURFACE BRIGHTNESS GALAXIES

Malin 1: A Bizarre Galaxy Gets Slightly Less So*: Hubble reveals a normal disk of stars at the center of this giant low surface brightness galaxy.

			ULTRADIFFUSE GALAXIES

Galactic Ghosts: Ghostly galaxies turn up in the Coma cluster.

814 Ghostly Galaxies Found in Famous Cluster*: Huge number may yield insight into how these galactic phantoms formed.

Ghostly Galaxies Are Light on Stars But Heavy on Dark Matter: The first measurement of an ultradiffuse galaxy's mass finds that dark matter makes up more than 99.96 percent of its mass.

The Mystery of Phantom Galaxies May Soon Be Solved: A new theory says these mysterious "ultradiffuse" galaxies are dwarfs born in a whirl.

The Milky Way's Dark Twin Revealed*: An almost invisible galaxy weighs as much as our own.

			GALAXY FORMATION

Hubble Spots the Farthest Spiral Galaxy Ever Seen: It flaunted its spiral arms just 3 billion years after the big bang.

Do Spiral Galaxies Form from the Inside Out?*: Distant spiral sheds light on galaxy formation.

Distant Galaxy Helped Relight the Universe*: It began forming stars only 150 to 300 million years after the big bang.

Tadpoles in Space: Exotic galaxies may provide snapshots of the Milky Way's youth.

Super Spiral Galaxies Amaze Astronomers*: A new breed of giants raises questions about how the biggest galaxies arise.

Low-Oxygen Dwarf Galaxy Shows Us How the Early Universe Looked: A star-forming galaxy with a record-breaking oxygen abundance probes conditions shortly after the big bang.

			CENTRAL BLACK HOLES IN GALAXIES

Giant Black Hole Shreds and Swallows Helpless Star: Astronomers watch the drama unfold from 2.1 billion light-years away.

Gargantuan Black Hole Occupies Modest Galaxy: It's one of the biggest black holes ever seen.

Supermassive Black Holes Reveal a Surprising Clue*: A startling correlation between the mass of a galaxy's central black hole and the number of globular clusters may give insights into galactic evolution.

Black Holes in Quasars Spin Fast*: The fast spins make quasars emit much more light than they otherwise would.

Danger: Black Hole Dead Ahead!: What may be a gas cloud is hurtling toward the Galaxy's biggest black hole.

			COLLIDING GALAXIES

Galactic Hit and Run*: Astronomers reconstruct a celestial accident.

Unveiling a Galactic Collision in Capricornus*: Two objects discovered during the nineteenth century are really colliding galaxies.

Galactic Collisions Spread The Wealth*: When galaxies collide, regions rich and poor in metals mix it up.

Why Some Galaxies Age Before Their Time: Ancient collision may explain why some young galaxies look old.

			QUASARS

Extreme Quasars Illuminate the Fast Lives of the First Black Holes: Recent discoveries of record-breaking quasars have pushed the boundaries of our understanding.

A Distant Quasar's Black Hole is Oddly Huge for its Galaxy*: The black hole powering the quasar has a record mass relative to the stars of the host galaxy.

A Distant Quasar May Be Zapping All Galaxies Around Itself*: Star formation has ceased within 16 million light-years of the quasar.

Black Holes in Quasars Spin Fast*: The fast spins make quasars emit much more light than they otherwise would.

Molecular Oxygen Spotted Beyond the Milky Way for the First Time: Sought for decades, the elusive molecule turned up in a quasar more than half a billion light-years away.

THE UNIVERSE

The Little Galaxies That Can: Star-making dwarf galaxies with just a trace of oxygen provide insight into the nature of the first galaxies, how they spawned their stars, and even the big bang itself.

A Record-Breaking, Oxygen-Starved Galaxy May Be Full of Gigantic Stars' Shrapnel*: The pristine galaxy provides a glimpse at conditions that prevailed in the early universe.

A Supernova's Delayed Reappearance Could Pin Down How Fast the Universe Expands: The catch: we have to wait until about 2037 for an answer.

The Lithium Problem: Why do the oldest stars have only a third as much lithium as big bang predictions say they should?

Pristine Relics of the Big Bang Spotted: Two distant gas clouds appear untouched by stars.

Charging Up the Universe*: When did the universe reionize itself? The Milky Way's oldest stars may hold the answer.

Did Runaway Stars Reionize the Ancient Universe?*: Hot stars booted out of their galactic homes may be responsible for creating the conditions that led to today's universe.

Distant Galaxy Helped Relight the Universe*: It began forming stars only 150 to 300 million years after the big bang.

Future of Cosmology Looks Bright in a Dark Universe: Cosmologists will still be able to do their job--even a trillion years from now.

Farthest Confirmed Galaxy Is a Prolific Star Creator: It shone just 700 million years after the big bang.

KEN CROSWELL'S ARTICLES IN ALPHABETICAL ORDER

The Age of Procyon*: The bright nearby star Procyon is 1.7 billion years old.

Air Apparent: Pluto's Eternal Atmosphere: New observations suggest the small world's air never vanishes.

An Ambitious New Mission Seeks the Origin of the Moons of Mars: Are Phobos and Deimos Captured Asteroids, or Did They Form After a Large Object Hit the Red Planet?

Andromeda's Vast Starry Disk*: M31 is a lot larger than it looks.

Andromeda X: Andromeda's Newest Satellite Galaxy: It's the dimmest galaxy ever seen orbiting Andromeda.

Another Earth 12 Light-Years Away?: Five planets may orbit Tau Ceti.

Astronomers Are Redrawing Our Corner of the Milky Way: Remarkable new observations are revealing the starry landscape of our Galactic neighborhood and our place within it.

Astronomers Have Found the Edge of the Milky Way*: Our Galaxy's total diameter is a whopping 1.9 million light-years.

Astronomers Measure Precise Distance to Controversial Star Cluster: But a top scientist blasts the result.

Astronomers Race to Learn from First Interstellar Asteroid Ever Seen: For the first time, we've seen an asteroid from another solar system visit our own.

Astronomers Uncover New Way to Measure the Speed of Stars: New observations now allow the seemingly impossible: determining how quickly some stars move toward us without measuring their Doppler shifts.

Baby Star Found on Earth's Doorstep*: The nearest pre-main-sequence star ever found may sport glowing planets.

Beta Centauri Weighs In*: Astronomers have measured the mass and distance of the eleventh brightest star in the night.

100 Billion Brown Dwarfs*: Brown dwarfs may rival the number of all normal stars in our Galaxy.

The Black Cloud: A frigid blob of gas and dust hovers nearby, possibly foreshadowing a stellar birth.

Black Holes in Quasars Spin Fast*: The fast spins make quasars emit much more light than they otherwise would.

The Blue Witch: The Witch Head Nebula shines by reflected glory from nearby Rigel.

The Brightest Red Dwarf: The brightest red dwarf resides in an obscure constellation, catalogued by an equally obscure pioneer in astronomy.

A Brightness Gap Exposes the Inner Lives of Red Dwarf Stars: Red dwarfs can pulsate.

Do Brown Dwarfs Pulsate?*: The least massive stars may resemble Cepheids.

Busted! Nearby Galaxy Is a Stellar Thief*: The Large Magellanic Cloud snatched stars from its long-time companion.

California Tornado Risk: Tornadoes hit California, too.

Cannibal Stars Explode Violently – as Predicted by Darwin’s Son*: Big star eats little star.

Captain Kirk Is Defeated at Pluto: William Shatner loses his battle to name a distant moon Vulcan.

Catching Andromeda's Light: The giant galaxy next door is a lot like ours.

The Cepheus Spur: A newly named feature in our Galaxy drapes distant luminaries across the northern sky from Cepheus and Camelopardalis to Auriga, Gemini, Taurus, and Orion.

Charging Up the Universe*: When did the universe reionize itself? The Milky Way's oldest stars may hold the answer.

Clocking the Hot Gas Gushing from the Milky Way's Core*: New observations of the Fermi bubbles indicate the Galaxy's core erupted 2.5 to 4 million years ago.

The Closest Star Cluster to Earth is in Its Death Throes*: Stars in the Hyades cluster are dashing past one another so fast it will disintegrate in only 30 million years.

"Cold" Hydrogen Molecules Found on Hot Stars*: Surprise discovery may probe the conditions on white dwarfs.

The Cosmic Origin of Carbon*: Most carbon on Earth came from stars that did not explode.

Dancing Stars Turn on the Red Light*: Two stars merge and trigger a rare type of nova.

Danger: Black Hole Dead Ahead!: What may be a gas cloud is hurtling toward the Galaxy's biggest black hole.

"Dark Sun" Is One of Our Nearest Neighbors: A newfound star less than 10 light-years from Earth appears to be the closest brown dwarf ever detected.

A Dash of Hydrogen and Methane Could Have Kept Mars Warm*: New calculations may solve the mystery of how ancient Mars got warm enough for rivers to flow.

Dawn of the Milky Way: New observations are unveiling the earliest years of our Galaxy.

Descendants of the Dipper: Heart of the best-known star pattern, the Ursa Major moving group probes the behavior of young stars and the chemical evolution of the Galaxy.

Diamond Planets Get Even More Precious: Carbon planets are a lot rarer than had been thought.

The Distance to a Stellar Youngster*: Astronomers pinpoint the parallax of T Tauri.

Distant Galaxy Helped Relight the Universe*: It began forming stars only 150 to 300 million years after the big bang.

A Distant Quasar May Be Zapping All Galaxies Around Itself*: Star formation has ceased within 16 million light-years of the quasar.

A Distant Quasar's Black Hole is Oddly Huge for its Galaxy*: The black hole powering the quasar has a record mass relative to the stars of the host galaxy.

Double Star Hosts Ancient World*: It's 2 billion years older than Earth.

Double Star May Light Up the Sky as Rare Red Nova in Six Years*: New observations of KIC 9832227 show it's on track to become a rare “red nova.”

The Drama Next Door: The Andromeda Galaxy is a giant spiral like the Milky Way but has had a surprisingly different, and tumultuous, past.

The Dumbbell Nebula's Harvest of Nitrogen: An expanding bubble enriches the Galaxy with nitrogen and may help life begin.

Dwarf Carbon Stars: Stars that shouldn't even exist may soon offer new clues to the ancient universe and the Galaxy's birth.

Can Dying Stars Support Life?: White dwarfs may have habitable planets.

"Earth-Mars" Collision May Have Hit Alien Solar System*: Did something whack a dim star's planet--and create a new moon?

814 Ghostly Galaxies Found in Famous Cluster*: Huge number may yield insight into how these galactic phantoms formed.

Elderly Couple Kicked Out of the Galaxy: Astronomers find the first old stars escaping from the Milky Way.

An Elemental Problem with the Sun: For two decades astronomers have been arguing over exactly how much carbon, nitrogen, and especially oxygen the Sun has--with implications for the entire universe.

Extrasolar Comets*: Here's how to see a comet around another star.

Extrasolar Neptune-Pluto Analogue Discovered: A newfound pair of extrasolar planets may boost the planetary prospects of Pluto.

Extreme Quasars Illuminate the Fast Lives of the First Black Holes: Recent discoveries of record-breaking quasars have pushed the boundaries of our understanding.

Famous Black Hole Confirmed After Forty Years*: The first parallax to Cygnus X-1 reveals that it must contain a black hole.

Far-out Earths Could Support Alien Life*: A life-bearing planet can exist far from its star--if its air abounds with hydrogen.

Far Out: The Most Distant Star in the Milky Way: A star 890,000 light-years away patrols our Galactic frontier.

Farthest Confirmed Galaxy Is a Prolific Star Creator: It shone just 700 million years after the big bang.

The Fastest Spinning Normal Star*: It spins 300 times faster than the Sun.

The Fastest Stars Escaping the Galaxy: Exploding white dwarfs can hurl their companions away at record speed, dooming them to roam intergalactic space for all eternity.

The Fate of the First Black Hole*: The black hole of Cygnus X-1 will likely separate from its long-suffering partner.

The First Binary Centaur*: The Hubble Space Telescope spots the first binary centaur ever seen.

The First Cepheid: The Cepheid story did not start with their namesake but with the largely overlooked star Eta Aquilae.

The First Cepheid Distance to Centaurus A*: The Hubble Space Telescope detects the first Cepheids ever seen in an elliptical galaxy--and measures its distance.

The First Cepheid Distance to NGC 55*: This galaxy may be orbiting another galaxy in the Sculptor group.

The First Dark Galaxy?*: Astronomers may have discovered a galaxy without stars.

First Detection of Thorium in Another Galaxy*: Thorium in the Ursa Minor dwarf galaxy offers the first chance to measure another galaxy's age via radioactive dating.

The First Direct Distance to Andromeda*: It agrees perfectly with less direct techniques.

The First Interstellar Gas in a Globular Cluster?*: Astronomers find evidence for hydrogen gas between M15's many stars.

First Noble Gas Molecules Found in Space: Argon hydride spotted in remnant of exploded star.

First Precise Distance to Shaula*: The second brightest star in Scorpius is a lot closer to Earth than astronomers had thought.

The First White Dwarf [cover story]: The road to discovering a new type of star was long and winding.

A Flare for Barnard's Star*: Just six light-years from the Sun, an old red star springs to life.

Fluorine: An Element-ary Mystery: The best-known ingredient in toothpaste has stellar origins that are anything but ordinary.

Fomalhaut Is Triple*: The bright star has a red dwarf companion--2.5 light-years away.

Found: The Fastest Approaching Object in the Universe: It has a record-setting blueshift of 1,026 kilometers per second.

Future of Cosmology Looks Bright in a Dark Universe: Cosmologists will still be able to do their job--even a trillion years from now.

Gaia Begins a Black Hole Revolution: Most black holes are quiet, and the Gaia spacecraft is starting to find them.

Galactic Collisions Spread The Wealth*: When galaxies collide, regions rich and poor in metals mix it up.

Galactic Ghosts: Ghostly galaxies turn up in the Coma cluster.

Galactic Hit and Run*: Astronomers reconstruct a celestial accident.

Galaxies Defy Astronomers' Expectations: Galaxies formed stars differently in the early universe.

The Galaxy Collision Next Door*: Two dwarf galaxies may have smashed together in our Local Group, sparking the nearest "starburst."

Galaxy Grande: Milky Way May Be More Massive Than Thought*: Hubble observations of a speedy galaxy weigh on the Milky Way and indicate that our Galaxy is at least a trillion times as massive as the Sun.

Galaxy Smash-Up Revealed Next Door: The Small Magellanic Cloud suffered a big collision 7.5 billion years ago.

The Galaxy's Youngest Globular Cluster?*: Whiting 1 may be as young as the Sun.

Gang of Gas Giants May Have Tilted Distant Solar System*: Astronomers pin down the likely culprit behind the first tilted solar system ever found.

Gargantuan Black Hole Occupies Modest Galaxy: It's one of the biggest black holes ever seen.

A Gargantuan Supernova Remnant Looks 40 Times Bigger than the Full Moon*: From Earth's perspective, it's the largest cloud of debris ever seen from an exploded star.

Gentle or Jumping? The Varied Lives of Hot Jupiters*: A newborn star's iron abundance foretells whether its gas giants face a violent future.

Ghostly Galaxies Are Light on Stars But Heavy on Dark Matter: The first measurement of an ultradiffuse galaxy's mass finds that dark matter makes up more than 99.96 percent of its mass.

Giant Black Hole Shreds and Swallows Helpless Star: Astronomers watch the drama unfold from 2.1 billion light-years away.

Giant Molecular Cloud in Solar Neighborhood: The California Nebula has a dark secret.

Giant Stars Bare Their Whirling Hearts: Their cores spins much faster than their surfaces.

A Giant Surprise*: Planet-bearing giant stars tend to be more metal-poor than other stars with planets.

"Goldilocks Stars" May Pose Problems for Any Nearby Habitable Planets*: Far-ultraviolet radiation from orange dwarfs could endanger planetary atmospheres.

Good News, Earthlings: The Planet Mercury Probably Won't Kill Us: Mercury may crash into Venus, but Earth is probably safe, if a new study is right.

Gould's Belt: Ring Around the Sky: Harboring some of the Milky Way's best-known features, Gould's belt lights the sky with superstars.

The Heaviest Neutron Star on Record Has 2.35 Times the Mass of the Sun*: The discovery helps refine the dividing line between neutron stars and black holes.

Here's How Cool a Star Can Be and Still Achieve Lasting Success*: The motions of nearby stars reveal the boundary between red dwarfs and brown dwarfs.

Here's the Best Timeline Yet for the Milky Way's Big Events: Our Galaxy formed its original disk 2 billion years before its stellar halo.

High-Speed Collisions Prevent Star Formation in Galactic Bars: Simulations of the stunning barred spiral galaxy NGC 1300 explain why its bar fails to sparkle with newborn stars.

Hopes Fade in Hunt for Planet X*: A newly determined mass for Neptune dooms Planet X, the hypothetical massive planet beyond Pluto.

The Horsehead Nebula is Rotating*: Astronomers give this famous nebula a spin.

Hot Jupiters Are Loners: Gas giants orbiting next to their suns have no close planetary neighbors.

Hot World Breaks Record*: It's the hottest planet yet.

How Hot Jupiters May Get Their Weirdly Tight Orbits*: Stars and neighboring planets can fling giant worlds toward their suns.

How Lithium Strips Brown Dwarfs of Their Red Disguise*: Here's how to tell a red dwarf from a brown dwarf.

How Many Stars Never Make the Big Time?*: Search for brown dwarfs reveals the odds of stellar success.

How Red Dwarfs Protect Their Planets*: Red dwarfs may protect their habitable planets better than the Sun protects the Earth.

How Tiny "Dead" Galaxies Get Their Groove Back and Make Stars Again*: Gas falling into a dwarf galaxy must fight the galaxy's own stars before making new ones.

How To Find Your Way Home from Deep Space: Astronomers unfurl a map more than a billion light-years across.

Hubble Finds Vast Reservoir of Gas Near the Milky Way: The Magellanic Stream may solve our Galaxy's impending gas shortage.

Hubble Spots the Farthest Spiral Galaxy Ever Seen: It flaunted its spiral arms just 3 billion years after the big bang.

Huge Stellar Nursery Found in Outer Galaxy*: It's more than ten times the size of the Orion Nebula.

Hyperactive Galaxy Could Run Out of Gas in Just 8 Million Years*: Nearby "starburst" galaxy is using up and blowing out far more gas than it takes it, astronomers warn.

Was Jupiter Born Beyond the Current Orbits of Neptune and Pluto? Conventional theory says Jupiter was born where it is now. Two groups of researchers working independently have proposed an intriguing alternative.

Is Jupiter Eating Its Own Heart?*: Some gas giant planets may have destroyed their cores.

Kamikaze Galaxy Explodes After Diving Into the Milky Way*: The Hercules dwarf has the most elliptical orbit ever seen for a Milky Way satellite galaxy.

Kepler Finds the First Tilted Solar System: Two planets circle their aging sun at a 45-degree angle.

The Life and Times of Sirius B*: Sirius was once even brighter.

The Lion's Pumpkin-Shaped Heart: Rapid rotation flattens Regulus.

The Lithium Problem: Why do the oldest stars have only a third as much lithium as big bang predictions say they should?

Little Galaxy's Own Stars Cast 95 Per Cent of Its Oxygen Away*: It's not easy being a little galaxy.

The Little Stars That Can: Surprising new observations reveal novae forging a lightweight metal whose price keeps going up and up.

The Lives of Red Dwarf Stars*: The closer a red dwarf is to the Galactic plane, the more likely it is to sport magnetic activity.

Low-Oxygen Dwarf Galaxy Shows Us How the Early Universe Looked: A star-forming galaxy with a record-breaking oxygen abundance probes conditions shortly after the big bang.

M67: The Ultimate Survivor: This ancient star cluster has cheated death for some 4 billion years.

Malin 1: A Bizarre Galaxy Gets Slightly Less So*: Hubble reveals a normal disk of stars at the center of this giant low surface brightness galaxy.

Mapping the Milky Way [cover story]: Recent years have seen tremendous strides in unraveling the Galaxy's spiral arms, and the next decade promises the best maps ever made of our celestial home.

Marsquakes Shake Up Views of the Red Planet's Deep Interior: The InSight spacecraft's seismometer sizes up the Martian crust, mantle, and core.

A Massive Star Dies Without a Bang: Evidence emerges that not all red supergiants explode, raising the possibility that Betelgeuse will never go supernova.

Mating Stars Hide Their Modesty Behind a Thick Veil of Dust: A torus of thick dust surrounds two stars that recently merged into one.

Meteorites from Mercury?: Some rocks on Earth are probably from Mercury.

The Mighty Milky Way: Our Galaxy is far bigger, brighter, and more massive than most others.

Milky Way Keeps Grip on Neighbor*: The Large Magellanic Cloud is here to stay.

The Milky Way Makes Little Galaxies Bloom, Then Snuffs Them Out*: Dwarf spheroidal galaxies light up with newborn stars when first approaching our Galaxy.

The Milky Way May Be Spawning Many More Stars than Astronomers Had Thought: Gamma rays reveal the Galaxy's star-making power.

Milky Way's Baby Brother Caught Copying Its Star-Shredding Habit*: The Large Magellanic Cloud is tearing apart a star cluster it may have stolen from another galaxy.

The Milky Way's Central Black Hole May Have Turned Nearby Red Giant Stars Blue: A powerful blast from the supermassive black hole may explain a lack of large, red stars there.

The Milky Way's Dark Twin Revealed*: An almost invisible galaxy weighs as much as our own.

The Milky Way's Dimmest Star Cluster*: Segue 3 ekes out just 90 Suns' worth of light.

The Milky Way's First Light*: In its youngest days, our Galaxy may have favored producing stars like Vega and Regulus.

The Milky Way's Most Massive Star Cluster May Have Eaten a Smaller Cluster: Observations of newfound stars suggest how the gathering of stars at the Galaxy's core grew so big.

The Milky Way's Newest Satellite*: Astronomers spot the dimmest galaxy ever seen--orbiting the Milky Way.

The Milky Way's Oldest and Wisest Stars: An astronomer invents a new technique to trace the origins of our Galaxy.

The Milky Way's Secret Companion?*: A large satellite galaxy may be lurking next to ours, hidden from sight.

The Milky Way Supernova You've Never Heard Of*: A newly measured distance to stellar debris in the northern sky ties it more firmly to an explosion observers saw in 1181.

Molecular Oxygen Spotted Beyond the Milky Way for the First Time: Sought for decades, the elusive molecule turned up in a quasar more than half a billion light-years away.

Most Planets on Tilted Orbits Pass Over the Poles of Their Suns*: The surprising discovery may reveal how misaligned worlds arise.

Most Stars Are Single*: Two thirds of all star systems are single, like the Sun.

Most Stars May Have Much More Time to Form Planets Than Previously Thought*: Planet-making disks may survive around many young stars for 5 to 10 million years.

The Mystery of Phantom Galaxies May Soon Be Solved: A new theory says these mysterious "ultradiffuse" galaxies are dwarfs born in a whirl.

Nearby Brown Dwarf Has Partly Cloudy Skies: Clues emerge to weather patterns on "hot Jupiters".

Nearby Galaxy Harbors Rarest Type of Black Hole: M82's black hole is 400 times as massive as the Sun.

Nearby Galaxy May Be Victim of Dark Matter Hit-and-Run: A dark subhalo may have punched a hole in spiral galaxy NGC 247.

Nearby Primitive Galaxies Offer a Window into the Early Universe: Galaxies just beyond the Local Group illuminate the nature of the first stars.

The Nearest Midsized Black Hole Might Instead Be a Horde of Lightweights*: A claim of an intermediate-mass black hole in a Milky Way star cluster comes under scrutiny.

Nearest Newborn Stars Discovered: A double star just 20 light-years from Earth is surprisingly young, offering bright prospects for planet hunters.

Neutrinos from Sun's Main Nuclear Reaction Detected: Numbers agree with the standard solar model.

Neutrinos Hint the Sun Has More Carbon and Nitrogen than Previously Thought*: Figuring out our star’s makeup is crucial for understanding the entire universe.

Never-Before-Seen Galaxy Spotted Orbiting the Milky Way*: The Crater 2 dwarf galaxy is our Galaxy's fourth largest satellite.

New Distance to the Orion Nebula*: The Orion Nebula is closer than you thought.

New Distance to the Orion Nebula, Part Two*: Parallax confirms a new, shorter distance to the Orion Nebula.

A New Image Captures Enormous Gas Rings Encircling an Aging Red Star*: The star is losing mass as it transforms into a white dwarf star.

Newly Found Brown Dwarf Is Ultracool*: It's room temperature.

New Moon Over Neptune: Hubble spots a new satellite around the distant giant planet.

A New Star in the Neighborhood*: Astronomers have found a dim red star in the Sun's backyard.

Ninth Rock From the Sun: It's time for a new and improved definition of "planet"--one that restores Pluto to its former glory.

Nitrogen in Pluto's Atmosphere*: Pluto is the only planet apart from Earth with an atmosphere consisting mostly of nitrogen.

No Home For Life in the Galactic Outer Suburbs*: If the Sun had been born near the edge of the Milky Way, we probably wouldn't exist.

No Ocean on Neptune--Yet*: Neptune has no ocean, but it may develop one in 8 billion years.

The North Star is Much Heavier Than Previously Thought*: Polaris is nearly 50 percent more massive than an earlier study found.

The Number of Milky Way Nova Explosions Per Year Has Been Pinned Down: Every year about four dozen of these stellar eruptions occur in our Galaxy.

Older Vega Is Mature Enough for Primitive Life*: The star of Contact is older than had been thought.

Oldest Minerals From Mars Found on Earth: New Martian meteorite sheds light on the red planet's earliest years.

One Black Hole Won't Ruin Your Day: If a primordial black hole hits Earth, you'll probably feel just fine.

Origins of a Mighty Meteor Shower [cover story]: How does a space rock make such a stunning display of shooting stars?

The Outer Milky Way's Exotic Origin*: Did a galactic collision create the stars in our Galaxy's outer disk?

51 Pegasi: Planet, Not Pulsation*: 51 Pegasi's planet is real.

Pinpointing a Stellar Neighbor*: A feisty red dwarf in Antlia becomes the Sun's 28th nearest neighbor.

Planets "Sing" in Three-Part Harmony*: Astronomers discover the first three-planet resonance--around a star just 15 light-years away.

The Pleiades' Lost Sister?*: An ultramassive white dwarf in Eridanus may have escaped from the Pleiades.

Pluto Question: How bright would Pluto be if it were as close as Mars?

Pluto Question 2: How bright would the brightest planets look if they were as far as Pluto?

Pluto's Egg-Shaped Neighbor Haumea Has a Ring No One Expected: It's the farthest ring ever seen in our solar system.

Pluto's Moons Offer Hints of Alien Worlds*: The distant satellites may show how planets orbit double stars.

Pluto's Revenge: Hubble Finds a Fifth Moon: Discovery boosts Pluto's planetary cred.

Poof! Planet-Forming Disk Vanishes Into Thin Air: The same cosmic mystery may have occurred in our solar system.

A Primordial Galaxy in Cetus?*: A nearby dwarf galaxy may be a pristine building block of large galaxies like our own.

Pristine Relics of the Big Bang Spotted: Two distant gas clouds appear untouched by stars.

Prodigal Gas Cloud Was Born in Milky Way and Is Crashing Back in*: Astronomers pinpoint the birthplace of a mysterious cloud in space.

A Protogalaxy in the Milky Way May Be Our Galaxy's Original Nucleus*: It's the kernel around which the Milky Way first formed.

Proxima Centauri Really Does Orbit Its Two Bright Neighbours*: After a century of speculation, astronomers confirm that Proxima Centauri revolves around Alpha Centauri A and B.

Proxima's Unprecedented Passage: When Stars Align: The Sun's closest stellar neighbor will soon reveal its mass--and possibly its planets--when it passes in front of a distant star.

Pulsar at the Galactic Center?*: It may be only one light-year from the Milky Way's central black hole.

Pulsar Will Put the Test to General Relativity: Trio of dead stars will subject Einstein's strong equivalence principle to its most stringest test ever.

A Pulsating Red Giant's Bow Shock*: The Spitzer Space Telescope detects a bow shock around R Hydrae.

Rainbow Whirlpools*: Two rainbow-colored images vividly show the differing distributions of the Whirlpool Galaxy's atomic and molecular hydrogen gas.

Record-Breaking Double Star May Be Cannibalising Itself*: An extreme binary “eclipses” Epsilon Aurigae by having an orbital period more than twice as long.

A Record-Breaking, Oxygen-Starved Galaxy May Be Full of Gigantic Stars' Shrapnel*: The pristine galaxy provides a glimpse at conditions that prevailed in the early universe.

Red Dwarfs With Planets Have Low Metallicities: Three of the nearest red dwarf stars with planets all have less iron than the Sun.

Red, Willing, and Able: Far from being desolate backwaters, red dwarfs may harbor an abundance of alien life.

The Return of a Great Nineteenth-Century Meteor Shower*: Long thought nearly extinct, the Andromedid meteor shower staged a surprise outburst last December—and may return in 2018 and 2023.

Runaway Stars May Create the Mysterious Ultraviolet Glow Around Some Galaxies*: The bright, young stars are located in regions where gas is too tenuous for new stars to form.

Did Runaway Stars Reionize the Ancient Universe?*: Hot stars booted out of their galactic homes may be responsible for creating the conditions that led to today's universe.

Saturn Has a Fuzzy Core, Spread Over More Than Half the Planet's Diameter*: A wave in one of the rings reveals the size and composition of the planet's core.

Saturn Is Shaking Its Rings*: Oscillations inside the giant planet perturb its rings, promising new clues to the nature of its enormous interior.

Saturn's First Trojan Asteroid Has Finally Been Discovered*: All four giant planets now have known asteroids sharing their orbits.

Scorpius Star is Twinned with Sun*: If you want to boost your chances of finding extraterrestrial intelligence, point your telescope at a star in the constellation of Scorpius.

Seeking Answers, Planetary Scientists Plot a Return to the Nearest Ice Giant: Uranus beckons.

A Shadowy Birthplace May Explain Jupiter's Strange Chemistry: A frigid planetary nursery could account for the gas giant’s peculiar atmospheric composition.

Shredded Galaxy Is Disintegrating Before Our Eyes After Smash-Up*: After collision with a neighbouring galaxy, the Small Magellanic Cloud may lose its ability to spawn new stars.

A Solar Twin in Serpens?*: A far-off star may be the Sun's close cousin.

A Solar Twin in the Big Dipper*: There's a star like the Sun in the Big Dipper.

Some of Uranus's Small Moons Are Doomed to Collide*: The first measurement of the mass of a small moon of Uranus suggests it will be obliterated after smashing into another satellite in the next million years.

Some Planets Are Alien Invaders*: Billions of stars in our Galaxy may have captured their most distant worlds.

The South American Appalachians: The Appalachians may be the remnant of an immense mountain range that once extended into Argentina.

Space is the Place for Impossible Molecules: Molecules containing noble gases don't form naturally on Earth. But they do in the interstellar medium.

Speedy Star Points to More Massive Milky Way*: The fastest halo star ever seen may boost estimates of our Galaxy's mass.

Spendthrift Spirals: The great spiral galaxies that adorn the modern universe are running out of gas and may someday lose their beautiful shapes.

Do Spiral Galaxies Form from the Inside Out?*: Distant spiral sheds light on galaxy formation.

Spiralling Arms Help Spread Oxygen Around for Future Planets*: The spiral arms of a galaxy named NGC 1365 contain 60 percent more oxygen than the space between, the most extreme variation ever seen.

A Star at the Edge of Eternity: A Saturn-sized star just 40 light-years away will outlive nearly all of its peers.

Star Birth Sparked at the Galaxy's Edge: Gas from another galaxy is hitting our own, triggering the birth of bright new stars and adding fresh luster to the Milky Way.

Starburst in Andromeda*: The giant Andromeda Galaxy owes a bit of its beauty to a galactic encounter.

A Star From Another Galaxy*: One of our nearest stellar neighbors--Kapteyn's Star, just 13 light-years from Earth--probably originated in another galaxy.

Star Performers: The Magellanic Clouds: Two intrepid galaxies dash past the Milky Way--and dazzle astronomers.

Stars Steal Their Planet's Moons: Hot Jupiters may be moonless.

Star Struck: Astronomers turn their telescopes to the unbounded beauty of the Milky Way.

Stars Without Galaxies*: Most of the intergalactic stars in the Virgo cluster are old and metal-poor.

The Star That Never Was*: Stardom is just a pipe dream.

A Stellar Discovery on the Far Side: Five remarkable stars on the other side of our Galaxy promise new insight into the outer reaches of our home turf.

The Stellar Origin of Copper*: The copper in pennies arose during the lives of stars like Rigel and Betelgeuse.

Stellar Theft Sends Guilty Star Into a Spin: A white dwarf explains why Regulus spins so fast it's not round.

The Story of T Tauri: An infant star in Taurus helped reveal a truth once thought radical: the universe still makes new stars.

The Story of Wolf 359: A little red sun in Leo was once the least luminous star known.

Strange Cosmic Radio Burst Pinned Down to Giant Stellar Nursery*: A young neutron star is probably the source of a strange repeating signal previously tracked to a dwarf galaxy 2.4 billion light-years away.

Sulfur Was Key to the First Water on Earth*: The find suggests all rocky planets get wet soon after birth, boosting the chances for life.

Can the Sun's Siblings Be Found?*: The Milky Way's spiral arms may have scattered the Sun's siblings hither and yon.

Super-Dim Galaxy May Be One of Hundreds Orbiting the Milky Way*: What may be the least luminous galaxy ever seen suggests our Galaxy has hundreds of equally dim satellites.

Supermassive Black Holes Reveal a Surprising Clue*: A startling correlation between the mass of a galaxy's central black hole and the number of globular clusters may give insights into galactic evolution.

A Supernova's Delayed Reappearance Could Pin Down How Fast the Universe Expands: The catch: we have to wait until about 2037 for an answer.

Super Spiral Galaxies Amaze Astronomers*: A new breed of giants raises questions about how the biggest galaxies arise.

Supervolcanoes Spotted on Mars: Colossal eruptions rocked the red planet's youth.

A Tail of Two Galaxies*: A dual origin for the Magellanic Stream?

Tadpoles in Space: Exotic galaxies may provide snapshots of the Milky Way's youth.

The Tenth Planet's First Anniversary: January 5 marks the date when the Sun's tenth planet was discovered.

The Three Moons of Pluto*: Astronomers determine the best orbits yet of Pluto's two new moons.

Tides Control the Geysers of Enceladus: Their strength depends on the moon's distance from Saturn.

Tides Turn Some "Habitable" Planets Into Hellish Hothouses*: Planets close to small red dwarfs may be "tidal Venuses."

Tilting Stars May Explain Backward Planets*: Stellar flips may explain some wrong-way planets.

Torn-Apart Galaxy May Be Exacting Revenge on the Milky Way*: The Sagittarius dwarf was massive enough to warp the galaxy that's tearing it apart.

Tracing Gold's Cosmic Origin Story: Astronomers thought they had finally figured out where the gold, platinum, and other heavy elements in the universe came from. In light of recent results, they’re not so sure.

Two New Galaxies Orbiting the Milky Way: Astronomers discover two satellites of our Galaxy in Boötes and Canes Venatici.

Unveiling a Galactic Collision in Capricornus*: Two objects discovered during the nineteenth century are really colliding galaxies.

Uranus and Neptune: The Neglected Planets [cover story]: Decades after a lone spacecraft flew by, the solar system's ice giants and their many moons still guard plenty of secrets.

Uranus Might Have Two Dark Moons We've Never Seen Before*: Newly detected wavy patterns in two of Uranus's rings suggest the possible presence of two small, unseen satellites.

The "USS Jellyfish" Emits Strange Radio Waves from a Distant Galaxy Cluster: Spanning 1.2 million light-years, the entity broadcasts a never-before-seen pattern of radio waves.

Venus: Doomed From the Start? The nearest planet probably never had oceans or life.

The Void Next Door [cover story]: An enormous region of darkness starts on our doorstep, giving astronomers their best chance to probe one of these gigantic cosmic structures.

Voyager Still Breaking Barriers Decades After Launch: As Voyagers 1 and 2 continue their epic journeys through interstellar space, they're resolving past controversies and even helping to spark a new one: the true shape of the heliosphere.

Wanted: New Worlds Beyond Pluto: Scientists work to keep an intrepid spacecraft busy.

Water Clouds Tentatively Detected Just 7 Light-Years from Earth*: They're the first water clouds seen beyond our solar system.

We Found Our Galactic Twin 180 Million Light-Years Away*: A galactic trio looks remarkably like the Milky Way and its two brightest companions, the Magellanic Clouds.

When Red Giants Were Young: One hundred years ago astronomers thought large, cool stars were destined to become stars like the Sun.

When the Magellanic Clouds Cozy Up to Each Other, Stars Are Born: Five synchronized peaks of star formation reveal the galaxies' most intimate encounters.

Who First Described the Comet Belt Just Beyond Neptune? It's time the so-called Kuiper Belt was finally rebranded.

Who Really Discovered Stellar Proper Motion? Contrary to many books and articles, the answer isn't who you think.

Why Intelligent Life Needs Giant Planets*: Without Jupiter and Saturn, intelligent life might never have arisen on Earth.

Why Jupiter's Big Moons Outnumber Saturn's: Jupiter 4, Saturn 1. Why?

Why Some Galaxies Age Before Their Time: Ancient collision may explain why some young galaxies look old.

The Widest Very Low Mass Binary*: Two faint red stars in Phoenix are traveling through space together--though separated by more than a hundred Sun-Pluto distances.

Will Mercury Hit Earth Someday?: The Sun's innermost planet may crash into Earth.

Wrong-Way Planets: Many extrasolar planets orbit their stars against the grain.

KenCroswell.com

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