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Earth-like planet GJ 1132b

April 7, 2017 | Expert Insights

Astronomers have found evidence for a hot and steamy atmosphere around an Earth-like planet that circles a red dwarf star in the southern sky. The discovery marks one of the first times that scientists have spotted an atmosphere around a small, rocky world and brings them one step closer to the goal of finding life elsewhere in the universe.

A rocky Earth-sized planet that circles a small, nearby star could be the most important world ever found beyond the solar system, astronomers say.

GJ 1132b

The planet lies in the constellation of Vela in the southern sky and is close enough for telescopes to observe any atmosphere it has, a procedure that could help spot life on other planets in the future.

GJ 1132b, the alien world is about 16% larger than Earth, and at 39 light years distant. It is three times closer than any other Earth-sized rocky planet yet found around another star. At that distance, it is hoped that telescopes will be able to make out the chemistry of its atmosphere, the speed of its winds and the colours of its sunsets.

Astronomers spotted the planet as it moved across the face of a red dwarf star only a fifth the size of the sun. Though much cooler and fainter than the sun, GJ 1132b orbits so close to its star that surface temperatures reach 260C.

Analysis

Using a telescope at the European Southern Observatory in Chile, the researchers were able to study the planet by watching how it blocked some of the light of its host star as it passed in front of it.

The searing temperatures are too hot for the surface to retain liquid water, making it inhospitable to life, but not so hot as to burn off any atmosphere that formed on the planet.

The observations of planet GJ 1132b suggest that it has a thick atmosphere containing either steam and/or methane. One possibility is that it is a 'water world' with an atmosphere of hot steam.

Assessment

it is unlikely that any life-forms could survive on this world, the discovery of an atmosphere is encouraging in the hunt for extra-terrestrial life. Planets around low mass stars can have atmospheres and because there are so many of those in the Universe, it makes it that much more likely that one might have life.

If the technology can detect an atmosphere today, then it bodes well for being able to detect and study the atmospheres of even more Earth-like planets in the not-too-distant future.