241–260 of 285 results


A Steamy Super-Earth?

For the first time, astronomers have detected the atmosphere of an exoplanet that is not a gas giant.


Planet from Another Galaxy

Astronomers have found a planet orbiting a very ancient, high-velocity, former red giant star that came from beyond the Milky Way.


How Many Earths?

A team of planet-hunting astronomers argue, based on discovery statistics, that Earth-mass worlds should be orbiting a quarter of stars like the Sun.

Sun and forming planets

Solar System

Our "New, Improved" Solar System

Recent computer models suggest a radical yet robust concept: in order to get the Sun's planets and asteroids arranged as they are today, Jupiter must have once been much closer to the Sun.


Watching a Planet's Death Spiral?

The exoplanet OGLE-TR-113b is already too close to its host star for comfort — and new observations suggest it's being gradually drawn inward to its doom.


"Potentially Habitable" Planet Found

Not too hot, not too cold, Gliese 581g orbits in the liquid-water temperature zone of a dim red-dwarf star just 20 light-years away.


Two Exoplanets in an Interactive Dance

Two transiting planets of the star Kepler 9 are tugging on each other and swapping orbital energy back and forth. And a third planet may be watching on.

Professional Telescopes

One Star, Seven Planets

European astronomers had found a bustling solar system in the southern constellation Hydrus: a Sunlike star with at least five and probably seven worlds swarming around it.


A Tidal Wave of Exoplanet Candidates

NASA's Kepler mission has found more than 700 stars that seem to have planets crossing their faces, mission scientists have announced. But it will take a lot of followup to separate the real ones from the false alarms.


Wrong-way Planets Confound Theorists

Planet-formation theory has been turned on its head by the discovery of planets that travel around their stars in retrograde orbits.


Exoplanet News Roundup

From little red dwarfs to big blue blazers, stars of all masses seem to form planets robustly. That's just one item from the latest crop of exoplanet news.


Kepler's First Exoplanet Results

NASA scientists announced this morning that the Kepler planet-hunting probe is working great, has produced a slew of results, and is working at high enough precision that it should be able to determine the abundance, or rarity, of Earth-size worlds galaxy-wide.


A Weird, Wonderful Waterworld?

The first super-Earth seen transiting its star has the same density as rocky Earth. Now a second one has a the same mass but a lower density — indicating that it's water almost all the way through, with a massive atmosphere to boot.


And Then There Were 400

Thirty new extrasolar planets are announced, including more super-Earths and some that orbit low-metallicity stars.


Super-Earth "Planet From Hell" Refined

CoRoT-7b, a hot super-Earth orbiting an orange dwarf in Monoceros, had proved to be rocky, not gaseous. It's truly a Dante-like inferno, with liquid-lava temperatures on one side and unearthly cold on the other.


CoRoT-7b, the Lava Planet

A "super-Earth" planet discovered last February turns out to be just as dense and rocky as Earth. But with its day side seared to perhaps 2,700°F, there might not be much solid ground to stand on.


Why Does Exoplanet WASP-18b Exist?

Observers have found a massive planet so close to its star that it orbits in less than a day. Either they were very, very lucky — or theorists really don't understand the inner workings of stars as well as they thought.

Exoplanets collide around HD 172555


Exoplanets' "Demolition Derby"

Within the past 1,000 years or so, two planet-size objects collided around the young star HD 172555 and created a titanic, white-hot fireball whose glassy ashes are still swarming around the star.

Spacecraft and Space Missions

Kepler Shows Its Promise

After just 1½ weeks of test observations, scientists are confident that the Kepler spacecraft is well on its way to discovering Earthlike planets around distant stars.

Stellar Science

Mapping Starspots by Exoplanet Transits

Astronomers have detected individual starspots by watching exoplanets cross in front of them. New advances may enable extensive mapping of stars' spottedness by this technique, filling gaps left by other methods.