Hot newfound planet may have cooler neighbours

An artist's impression of Alpha Centauri B, with an unnamed planet to the right Keystone

Astronomers at Geneva University have found a planet similar to Earth – but it is so hot that the surface is probably like molten lava. Still, the discovery means that there may be more inhabitable planets circling that same star: Alpha Centauri B.

This content was published on October 17, 2012 - 13:47 and agencies

The research, done by a team of European astronomers based at the observatory in the Swiss city of Geneva, was released online on Tuesday in the journal Nature, and will appear in Thursday’s hardcopy.

In terms of mass, the planet is roughly the same size as Earth. But unlike Earth, it only needs three days to circle its star rather than 365. In other words, it is much closer to Alpha Centauri B than Mercury is to our Sun, and its temperature is estimated to be a roasting 1,200°C. Nevertheless, the yet-to-be-named planet has sparked the hopes of researchers.

“There’s a very good prospect of detecting a planet in the habitable zone that is very close to us,” said Geneva Observatory’s Stephane Udry, head of a team of European planet hunters.

There is a competition underway between American and European scientists to see who can find the closest and most Earth-like exoplanets – which are planets outside the Earth’s solar system.

At 40 trillion kilometres away, this one is about four light years away from Earth. To date, scientists have found more than 800 but say there could be billions. Yet an abundance of starlight has made the search a challenge.

According to Geneva Observatory’s Xavier Dumusque, the lead author of the study, Alpha Centauri B is so close to Earth that its brightness almost obliterates the view of any nearby planets.

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