More and more, if looks as if we ever do go out there, we'll have places to go. Reuters brought the word:
European astronomers have spotted what they say is the most Earth-like planet yet outside our solar system, with balmy temperatures that could support water and, potentially, life.Most of the 200-plus extrasolar planets found so far are gas giants similar to Jupiter, largely because the most common way to find such planets is by their gravitational effect on their star - and large planets orbiting close to the star will produce the largest effect and thus be the easiest to find. This one, by comparison, appears to have about 5 times Earth's mass; Jupiter's mass is about 318 times that of Earth.
They have not directly seen the planet, orbiting a red dwarf star called Gliese 581. But measurements of the star suggest that a planet not much larger than the Earth is pulling on it, the researchers say in a letter to the editor of the journal Astronomy and Astrophysics.
"This one is the first one that is at the same time probably rocky, with water, and in a zone close to the star where the water could exist in liquid form," said Stephane Udry of the Geneva Observatory in Switzerland, who led the study. ...
"On the treasure map of the universe, one would be tempted to mark this planet with an X" [added team member Xavier Delfosse of Grenoble University in France].
Note that the discovery does not mean the planet has water (it could have been boiled away during an earlier epoch when its sun was hotter), only that it could have water and if it does it would be liquid. What's more, this is not the first rocky, Earth-type (as opposed to gaseous) planet found - it is, however, the most Earthlike so far. As techniques continue to improve, more such planets are likely to be found.
In fact, it's believed that fairly soon, within 20 to 30 years, it will be possible to block the light from the star and so obtain spectrographic images of light reflected from the planet itself - which could even reveal, assuming there is any, the signature of plant life there. And wouldn't that be something.