HUGE NEWS: first possibly Earthlike extrasolar planet found!

Artist's impression of the planetary system around Gliese 581. Courtesy ESO. The European Southern Observatory is reporting that they have found the most Earthlike planet yet orbiting another star. It has about 1.5 times the Earth's diameter, and five times its mass. This makes it the smallest extrasolar planet yet found (two other planets have already been found orbiting that star, with 15 and 8 times Earth's mass). This is amazing enough! But it gets far, far better. The parent star, Gliese 581, is a red dwarf, meaning it's smaller and cooler than the Sun. The as-yet unnamed planet orbits this star much closer than the Earth does the Sun; it stays about 11 million kilometers (6.7 million miles) from its star, while the Earth is 150 million km (93 million miles) from the Sun. But remember, Gliese 581 is cooler than the Sun, so at this distance the planet ...