| BOOKS | F. A. Q. | ARTICLES | TALKS | ABOUT KEN | ORDER BOOKS | BEYOND OUR KEN |
|---|
| VIEW ARTICLES BY SUBJECT | VIEW ARTICLES IN ALPHABETICAL ORDER |
|---|
| KEN CROSWELL'S ARTICLES BY DATE |
|---|
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.
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 PLANETS |
|---|
| 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.
| JUPITER AND SATURN |
|---|
Why Intelligent Life Needs Giant Planets*: Without Jupiter and Saturn, intelligent life might never have arisen on Earth.
| NEPTUNE |
|---|
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?
| 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.
| THE STARS |
|---|
Most Stars Are Single*: Two thirds of all star systems are single, like the Sun.
| INTERSTELLAR MEDIUM |
|---|
The Black Cloud: A frigid blob of gas and dust hovers nearby, possibly foreshadowing a stellar birth.
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.
| STAR FORMATION |
|---|
The Distance to a Stellar Youngster*: Astronomers pinpoint the parallax of T Tauri.
| 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.
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.
First Precise Distance to Shaula*: The second brightest star in Scorpius is a lot closer to Earth than astronomers had thought.
| A-TYPE MAIN-SEQUENCE STARS |
|---|
The Life and Times of Sirius B*: Sirius was once even brighter.
| FGK MAIN-SEQUENCE STARS |
|---|
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.
| RED DWARFS |
|---|
Red, Willing, and Able: Far from being desolate backwaters, red dwarfs may harbor an abundance of alien life.
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.
| BROWN DWARFS |
|---|
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 |
|---|
The First Cepheid: The Cepheid story did not start with their namesake but with the largely overlooked star Eta Aquilae.
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.
| 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 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.
| NEUTRON STARS AND PULSARS |
|---|
Pulsar at the Galactic Center?*: It may be only one light-year from the Milky Way's central black hole.
| STAR CLUSTERS |
|---|
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 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 |
|---|
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 |
|---|
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.
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.
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.
| EXTRATERRESTRIAL LIFE |
|---|
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.
| THE GALAXIES |
|---|
| THE MILKY WAY |
|---|
The Outer Milky Way's Exotic Origin*: Did a galactic collision create the stars in our Galaxy's outer disk?
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.
| MILKY WAY SATELLITES |
|---|
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.
| THE ANDROMEDA GALAXY |
|---|
Catching Andromeda's Light: The giant galaxy next door is a lot like ours.
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 SCULPTOR GROUP |
|---|
The First Cepheid Distance to NGC 55*: This galaxy may be orbiting another galaxy in the Sculptor group.
| 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 |
|---|
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.
| 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.
| COLLIDING GALAXIES |
|---|
Unveiling a Galactic Collision in Capricornus*: Two objects discovered during the nineteenth century are really colliding galaxies.
| QUASARS |
|---|
Black Holes in Quasars Spin Fast*: The fast spins make quasars emit much more light than they otherwise would.
| THE UNIVERSE |
|---|
Charging Up the Universe*: When did the universe reionize itself? The Milky Way's oldest stars may hold the answer.
| KEN CROSWELL'S ARTICLES IN ALPHABETICAL ORDER |
|---|
The Age of Procyon*: The bright nearby star Procyon is 1.7 billion years old.
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.
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.
Do Brown Dwarfs Pulsate?*: The least massive stars may resemble Cepheids.
Catching Andromeda's Light: The giant galaxy next door is a lot like ours.
Charging Up the Universe*: When did the universe reionize itself? The Milky Way's oldest stars may hold the answer.
The Cosmic Origin of Carbon*: Most carbon on Earth came from stars that did not explode.
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.
The Distance to a Stellar Youngster*: Astronomers pinpoint the parallax of T Tauri.
The Dumbbell Nebula's Harvest of Nitrogen: An expanding bubble enriches the Galaxy with nitrogen and may help life begin.
Extrasolar Comets*: Here's how to see a comet around another star.
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 Precise Distance to Shaula*: The second brightest star in Scorpius is a lot closer to Earth than astronomers had thought.
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.
The Galaxy's Youngest Globular Cluster?*: Whiting 1 may be as young as the Sun.
A Giant Surprise*: Planet-bearing giant stars tend to be more metal-poor than other stars with planets.
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.
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.
How Lithium Strips Brown Dwarfs of Their Red Disguise*: Here's how to tell a red dwarf from a brown dwarf.
The Life and Times of Sirius B*: Sirius was once even brighter.
The Lion's Pumpkin-Shaped Heart: Rapid rotation flattens Regulus.
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.
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.
Meteorites from Mercury?: Some rocks on Earth are probably from Mercury.
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 Newest Satellite*: Astronomers spot the dimmest galaxy ever seen--orbiting the Milky Way.
Most Stars Are Single*: Two thirds of all star systems are single, like the Sun.
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 Star in the Neighborhood*: Astronomers have found a dim red star in the Sun's backyard.
Nitrogen in Pluto's Atmosphere*: Pluto is the only planet apart from Earth with an atmosphere consisting mostly of nitrogen.
No Ocean on Neptune--Yet*: Neptune has no ocean, but it may develop one in 8 billion years.
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.
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?
A Primordial Galaxy in Cetus?*: A nearby dwarf galaxy may be a pristine building block of large galaxies like our own.
Pulsar at the Galactic Center?*: It may be only one light-year from the Milky Way's central black hole.
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.
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.
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.
Stars Without Galaxies*: Most of the intergalactic stars in the Virgo cluster are old and metal-poor.
The Stellar Origin of Copper*: The copper in pennies arose during the lives of stars like Rigel and Betelgeuse.
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.
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.
Why Intelligent Life Needs Giant Planets*: Without Jupiter and Saturn, intelligent life might never have arisen on Earth.
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.
| BOOKS | F. A. Q. | ARTICLES | TALKS | ABOUT KEN | ORDER BOOKS | BEYOND OUR KEN |
|---|