by Matthew Cobb
A report in The Guardian describes the discovery of an apparently Earth-like planet in orbit around Gliese 581, a red dwarf star about 20 light years away. The key point is that Gliese 581g – as it has been romantically dubbed by the astronomers – is rocky (unlike the vast majority of exoplanets thus far discovered), it has sufficient gravity to potentially maintain an atmosphere and that it is in the “Goldilocks zone” – not so close to its sun that everything would fry, and not so far that everything would freeze.
That having been said, I don’t think we’ll be firing up the warp drive just yet to go and colonise it. Like our Moon, Gliese 581g keeps one face permanently to the sun, the other permanently facing the sidereal gloom. In other words, it would be extremely hot on one side, extremely cold on the other and just right only in a narrow band between the two.
Nevertheless, Steven Vogt, an astronomer at the University of California, Santa Cruz, is quoted as saying “Any emerging life forms would have a wide range of stable climates to choose from and to evolve around, depending on their longitude”. This seems to be jumping the gun somewhat, given they have – literally – only the slightest glimmer to go on. A more important point made by Vogt would seem to be this: “The fact that we were able to detect this planet so quickly and so nearby tells us that planets like this must be really common.”