Astronomers have identified a star system just 22 light years from Earth with three planets that could potentially harbor life. The Gliese star system is easy to locate in the constellation Scorpius. The two main stars, Gliese 667A and B, are visible to the naked eye, but the one with the planets, Gliese 667C, requires a telescope to see. Gliese 667C has 7 planets, and 3 of them are in its habitable zone, which is the region around the star where temperatures would not be too high or too low for life to form, and where water would be a liquid. Earth is near the center of the sun’s habitable zone, and Venus and Mars are at its extremes.
On the habitable planets, Gliese 667C would give a red light, while the other two stars in the system, from farther away, would create a light level equivalent to the moon.
Scientists now think that our galaxy may be literally teeming with planets that could harbor life, meaning that it might be quite literally commonplace. Intelligent life, though, is another question. Right now, we cannot detect anything except the orbit and probable size of extra-solar planets. To be more certain of whether or not they are living systems, we would need to be able to determine if liquid water was present, and the composition of the atmosphere.
Newer, more sensitive telescopes are planned both in the US and the EU that will do just that.