Extraterrestrial liquid water
The Gliese 581 planetary system contains multiple planets that may be candidates for surface water, including Gliese 581c, Gliese 581d, might be warm enough for oceans if a greenhouse effect was operating, and Gliese 581e.
Lake Whillans
These projects may yield insights into the search for life elsewhere in the Solar System. In particular, the moons Europa (Jupiter) and Enceladus (Saturn) have large amounts of liquid water beneath icy crusts.