Scientists believe that they have discovered a planet that is suitable for life. Gliese 581d could have the right conditions to support life.
Gliese 581d, a planet orbiting the red-dwarf star Gliese 581, is the first confirmed potentially-habital extrasolar planet. French scientists used complicated computer models to assess the atmosphere on Gliese 581d, and have found that it falls into the goldilocks zone (a planet that is not too cold and not too hot, but just right).
But Gliese 581d does have it’s drawbacks, and may not be suitable for human life. First off, it would take about 3000 lifetimes to get there. Secondly, the planet is tidally locked, which means there is no day and no night. One side is perpetually in light, while the other side is perpetually dark. Pop Science also reports that since Gliese 581d has a much larger mass than earth, the gravity would be about twice as strong on the surface of Gliese 581d.
Still, the potential for life outside of earth exists on Gliese 581d.
[Source: Pop Science]