A team of European scientists has discovered what may be an Earth-like planet, capable of sustaining life, orbiting a red dwarf star in the constellation Libra. The smallest planet yet discovered, it has a mass of about 5 times that of Earth and, depending on unknown variables like density and how much light the planet reflects, its surface could contain water and average a comfortable zero to forty degrees Celsius. Dimitar Sasselov of the Harvard-Smithsonian Center for Astrophysics told the New York Times that the find is especially exciting because, not only is it close enough for humans to travel to someday, it "basically tells you these kinds of planets are very common." The planet, he said, is probably very stable geologically, meaning it could be even friendlier to life than Earth is.

Source: Dennis Overbye, New Planet Could Be Earthlike, Scientists Say. New York Times, April 25, 2007. Photo: Artist's rendering of Gliese 581 as seen from the newly-discovered planet. Image © ESO.