New Earth-sized exoplanet found in our own 'backyard'

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Published time: October 17, 2012 13:03
Edited time: October 17, 2012 23:43

The discovery of a planet in the closest star system to our own has rocked the astronomy world. It is just 4.3 light years away from Earth, and has sparked hope of finding other less-hot and potentially habitable planets nearby.

It doesn’t support life, but astronomers are hopeful that others in the area can.

It is just 4.3 light years (25 trillion miles) away and even though it is of similar size to Earth, it is too close to its sun to support life, with a surface temperature estimated at 1,200 degrees Celsius (2,192 Fahrenheit).

The new planet, dubbed Alpha Centauri Bb, is much closer to that star than Mercury is to our sun. The planet’s orbit is 25 times smaller than ours, so a year on this planet passes in just 3.2 Earth days.

The new find was announced in science journal Nature by Stephane Udry and Xavier Dumusque at the Geneva Observatory.

"It's a landmark discovery because it's very low mass and it's our closest neighbor," Udry told Reuters.

Both the astronomers predict that there are other planets circling the same star a little farther away, where it may be cool enough for water and life.

“Finding in our closest neighbor a one-Earth-mass planet really opens up the prospect for finding planets there in the habitable zone,” Udry told Wired Magazine.

It's the nearest out of all the exoplanets yet discovered. The term “exoplanet” refers to planets outside our Solar system, and every finding of this kind is of great scientific and potentially practical importance, as it increases the chances of finding life-supporting worlds like our own.

Previously, the closest exoplanet discovered to Earth was Gliese 876 d, which is 15 light-years away.

"This is our backyard, so to find out that planet formation occurred there is just extraordinary," said university of California astronomer Greg Laughlin.

The star Alpha Centauri B that the newly discovered planet is orbiting is a bit smaller, dimmer and more yellow than our sun and it sits in Alpha Centauri system, which contains three stars.