DR MEHMOODZAI
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Astronomers discover Earth-like planet
Updated : Friday December 18 , 2009 10:41:37 AM
HARVARD: A rocky and water-rich planet, not much heftier than our Earth, has been discovered so close to our solar system that astronomers one day may be able to study its atmosphere.
And though astronomers are pretty certain the water exists, they don't know its state, with speculations ranging from liquid water to water ice and an exotic state called a superfluid.
The extrasolar planet, now named GJ 1214b, is about 40 light-years away. It orbits a red dwarf star. It is the only known "Super-Earth" exoplanet worlds that have masses between Earth and Neptune with a confirmed atmosphere.
"Astronomically speaking, this planet is on our block," meaning it's in our cosmic neighborhood, said study leader David Charbonneau of the Harvard-Smithsonian Center for Astrophysics in Mass. "For perspective, our own TV signals have already passed beyond the distance of this star."
The planet is about three times the size of Earth and about 6.5 times as massive. It is the second smallest planet discovered outside of our solar system to date, trailing behind only CoRoT-7b, which is 1.7 times Earth's size and about five times as massive.
GJ 1214b is rare among known rocky exoplanets because it partially eclipses, or transits, its star as seen from Earth.
This fortunate alignment allows astronomers to calculate the size and density of the planet, and Charbonneau's team thinks GJ 1214b is likely a water world with a solid center. Moreover, the planet has a thick surrounding atmosphere of hydrogen and helium.
Normally, a planet located at that distance from this particular type of star would be so hot that any water on its surface would be in a vapor form.
But scientists think the thick atmosphere of this planet creates a high pressure environment that keeps water on the surface in a liquid state.
Astronomers discover Earth-like planet
Updated : Friday December 18 , 2009 10:41:37 AM
HARVARD: A rocky and water-rich planet, not much heftier than our Earth, has been discovered so close to our solar system that astronomers one day may be able to study its atmosphere.
And though astronomers are pretty certain the water exists, they don't know its state, with speculations ranging from liquid water to water ice and an exotic state called a superfluid.
The extrasolar planet, now named GJ 1214b, is about 40 light-years away. It orbits a red dwarf star. It is the only known "Super-Earth" exoplanet worlds that have masses between Earth and Neptune with a confirmed atmosphere.
"Astronomically speaking, this planet is on our block," meaning it's in our cosmic neighborhood, said study leader David Charbonneau of the Harvard-Smithsonian Center for Astrophysics in Mass. "For perspective, our own TV signals have already passed beyond the distance of this star."
The planet is about three times the size of Earth and about 6.5 times as massive. It is the second smallest planet discovered outside of our solar system to date, trailing behind only CoRoT-7b, which is 1.7 times Earth's size and about five times as massive.
GJ 1214b is rare among known rocky exoplanets because it partially eclipses, or transits, its star as seen from Earth.
This fortunate alignment allows astronomers to calculate the size and density of the planet, and Charbonneau's team thinks GJ 1214b is likely a water world with a solid center. Moreover, the planet has a thick surrounding atmosphere of hydrogen and helium.
Normally, a planet located at that distance from this particular type of star would be so hot that any water on its surface would be in a vapor form.
But scientists think the thick atmosphere of this planet creates a high pressure environment that keeps water on the surface in a liquid state.
