Distant planet judged possibly habitable

There are some details at:
http://en.wikipedia.org/wiki/Gliese_581_c
including a link to the PDF of the paper.

One of the striking things is that it is only 20 light-years away.

Nice to see the planet-finding techniques gradually getting more
sensitive. If the trend continues, we'll continue to push the
envelope in terms of how small a planet we can find.

Although what really makes this one part of the "habitable zone" is
that it is orbiting a rather dim star. So it can be close to the star
(and thus easier to detect) while not getting super-hot like Mercury.