The Search for Extra Terrestrial Intelligence, or SETI, has made a business of looking for signs of intelligence in the universe. Recent data from a team of astronomers at UC Santa Cruz and the Carnegie Institute for Science have given SETI a promising place to focus their attention: Gliese-581 g, a planet 20 light-years away, in the ‘habitable zone’ around the red dwarf star Gliese-581. Many factors determine whether a planet is habitable or not, ranging from the obvious variables, such as distance to the star and the star’s luminosity, to the less obvious variables, such as whether or not the planet has a large enough moon to keep its rotation stable or a giant neighbor (such as Jupiter) to sweep away dangerous incoming asteroids.
This discovery, made with the help of the new Kepler spacecraft, suggests that Gliese-581g may have the right conditions for liquid water, considered by many exobiologists (or astrobiologists: those who theorize about extra-terrestrial life) to be essential for life.
However, some have argued that since it’s not life but intelligence that we’re really after, the habitable zone may be the wrong place to look. Continue reading “Astronomers find ET habitability, but only for the biological.”