Astronomers based at the European Southern Observatory at La Silla, Chile have discovered what looks to be the most Earth-like planet so far observed. Scientists involved in the study of exoplanets (planets outside our solar system), believe conditions on the distant world may be right for liquid water to exist on the surface. This would make it by far the most likely candidate to support life as we know it. The planet, some 20 light years away, is approximately one and a half times the size of Earth orbiting a red dwarf star known as Gliese 581 in the constellation of Libra. It is 14 times closer to its star than the Earth is to our sun, but based on its position, scientists estimate the average surface temperature to be somewhere between 0 and 40 degrees. This raises the possibility that it may be covered with oceans. Most of the 200 or so exoplanets already identified are gas giants such as Neptune or Jupiter. This is because they are easier to spot. Very large planets that closely orbit stars exert a gravitational force which causes a telltale wobble that can be observed by astronomers. Smaller exoplanets are trickier to identify, though the dimmer light emitted by red dwarfs can make the process easier. As yet, the new planet has not been given a name – it is being referred to as Gliese 581c. The International Astronomical Union will only officially name it when an image of the planet has been obtained. However, if you have any bright ideas for a suitable name, or indeed any other thoughts you'd like to share,the subject of new Earth is open for discussion on the messageboards.

Published on 26 April 2007