January 25, 2004

　　

Lake Vida, Antarctica, 1997

Photograph by Maria Stenzel

A geologist hikes above a lake covered by some 19 meters [62 feet] of ice. Despite Antarctica's extreme temperatures, the lake is perpetually liquid, its freezing point lowered because of its high salinity—seven times that of sea water.

　　

Scientists found 2,800-year-old microbes in the ice above the lake. They came to life when thawed. Studying this lake's ecosystem could yield clues about life on Mars, where frozen surface water is speculated to hold life-forms.

　　

(Photograph shot on assignment for, but not published in, "Timeless Valleys of the Antarctic Desert," October 1998, National Geographic magazine)