Planets

Reaching a milestone in the search for Earth-like planets in the universe, two teams of astronomers say they have parted the curtains of space to take the first pictures of planets beyond our solar system. The first team, led by UC Berkeley researchers, used the Hubble Space Telescope to take a picture of a giant planet orbiting the star Fomalhaut, 25 light-years away. "It's almost science fiction," said Berkeley astronomer Eugene Chiang.

Evidence of water has been detected for the first time in a planet outside our solar system, an astronomer says -- a tantalizing find for scientists eager to know whether life exists beyond Earth. The research will be published in the Astrophysical Journal. Travis Barman, an astronomer at Lowell Observatory in Flagstaff, Ariz., said Tuesday that water vapor had been found in the atmosphere of a large, Jupiter-like gaseous planet 150 light-years from Earth.

European astronomers announced Tuesday that they had discovered the first planet beyond our solar system that orbits in a "sweet spot" zone where life could exist. The planet, about five times as massive as Earth, orbits Gliese 581, a red dwarf star about 20 light-years from our solar system. The team of Swiss, French and Portuguese scientists who found the planet estimate its surface temperature at freezing to 104 degrees Fahrenheit, a range in which water can exist as a liquid.

A hot snowball sounds as contradictory as a frosty forest fire, but European astronomers think they've found one orbiting a dwarf star about 33 light-years from Earth. The strange planet, GJ 436 b, is about the size of Neptune. It orbits a red dwarf star about half the mass of the sun but 100 times dimmer. The coolness of the star is a major reason water can persist on the planet's surface, according to research published this week in the journal Astronomy & Astrophysics.

An international team of astronomers on Monday announced the discovery of 28 planets outside the solar system, the greatest single haul since the first so-called exoplanet was found 12 years ago. Still eluding the planet hunters, however, is the much-longed-for Earth replica, a planet like ours that could nourish some kind of life, allowing humans to feel a little less lonely in the cosmos.

For the first time, astronomers have spotted water on a planet beyond the solar system. The planet, a gas giant similar to Jupiter known as HD 189733b, orbits a star 63 light-years from Earth in the constellation Vulpecula, according to a study published Thursday in Nature. European astronomers studied its outer atmosphere while it passed in front of its star. As light pierced the atmosphere, it revealed characteristics suggesting the presence of water molecules, the study said.

Scientists have discovered the universe's largest known planet, a giant ball made mostly of hydrogen that is 20 times larger than Earth and circling a star 1,400 light-years away in the constellation Hercules. Scientists think the planet has 1.7 times the diameter of Jupiter, the largest planet in our solar system, and a temperature of 2,300 degrees. "There is probably not a really firm surface anywhere on the planet.

Astronomers have discovered a new planet orbiting a sun-like star 41 light-years away, marking the first known planetary quintet outside our solar system. The newfound planet and four others circle the star 55 Cancri in the constellation Cancer, the researchers said this week. Although it resides in the star's so-called habitable zone, a place where liquid water and mild temperatures should exist, it is more like Saturn than Earth and therefore not likely to support life.

For the last 20 years, UC Berkeley astronomer Geoff Marcy has been the world's leading planet finder. Of the 260-odd planets that have been discovered in other solar systems, Marcy and his team have found 150. His most recent discovery, announced last week, is a fifth planet orbiting a star called 55 Cancri, about 41 light-years from Earth. Marcy, 53, sat down in his office to talk about the friendly and not-so-friendly competition to find the first Earth-like planet that could harbor life.

Astronomers say they've found what may be the smallest and most distant planet known to be orbiting a star outside our solar system. The find suggests that such small rocky or icy planets may be more common in the cosmos than Jupiter-sized gas giant planets, researchers reported this week in the journal Nature. All such planets, known as exoplanets, discovered around distant stars have been larger than Earth. This one is about 5.