Planet discovered in star's Goldilocks zone

There has been a third planet discovered orbiting the star Gliese 581 in the constellation Libra. The planet is approximately 5 times as massive as the earth and is closer to its star than Mercury is to the Sun.

There have been over 200 exoplanets discovered so far, but most of them have been hot gas giants which are unlikely to support life, at least as we know it. However, Gliese 581 is a red dwarf type star, which means it is a lot cooler than the Sun, and this new planet is orbiting in the stars Goldilocks zone, not too hot - not too cold - but just right for water to exist in its liquid phase.

So if the planet is of the rocky-type, has water, and if its atmosphere is of the right composition, not too thick and not too thin, then it may be habitable. Those are pretty big ifs and planets like these are not thought to be rare but what is significant is that this planet is only 20.5 light years away from the Earth. This distance is large but not insurmountable.