[troutman]

Originally Posted by worth

All you need is a rock in a habitable zone orbit which makes for liquid water. Thats the basis for life right there.

SETI:

http://www.planetary.org/explore/topics/seti/

Astronomers think they will soon to able to detect planets with water in the habitable zones near other stars.

http://www.planetary.org/explore/top...ts/extrasolar/

http://www.planetary.org/news/2006/0...nt_Planet.html

One reason is the new planet's mass. At around five times the mass of Earth, the new planet, designated OGLE–2005-BLG-390Lb, is the lowest-mass planet ever detected outside the solar system. And when one considers that the vast majority of the approximately 170 extrasolar planets detected so far have been Jupiter-like gas giants, dozens or hundreds of times the mass of Earth, the discovery of a planet of only five Earth masses is indeed good news.

But there is more: astronomers believe that the detection of OGLE–2005-BLG-390Lb, announced in the January 26 issue of the journal Nature, is a strong indication that terrestrial-type planets are plentiful, probably much more so than gas giants. And if this is so, then it is quite possible that among these numerous rocky planets there are some that resemble the Earth.