Developments in Brief : Lakes Hold Possibility of Life on Ancient Mars

Ice-covered lakes on ancient Mars could have spawned life at one time, National Aeronautics and Space Administration scientists said last week.

Astrophysicist Christopher McKay and biologist Robert Wharton said their conclusions come from comparative studies of seven Antarctic lakes and the dry beds of what photographs indicate were once giant lakes in a 3,000-mile-long canyon system near Mars’ Equator.

McKay said that if life did evolve on Mars, it probably would have been destroyed billions of years ago when the planet cooled and lost much of its atmosphere. “It’s highly unlikely life could exist on Mars today,” he said.

The researchers said a complex process that keeps the Antarctic lakes at temperatures up to 77 degrees Fahrenheit despite ice coverings up to 15 feet thick also could have trapped heat and concentrated dissolved gases in Martian lakes.

Photographs taken by the Viking mission show layered sediments on the floor of the Martian canyon called Valles Marineris. Scientists said the flatness and apparent consistency in thickness suggest that the sediments were laid down in water.

“It’s an almost inescapable conclusion,” said Michael Carr, planetary geologist with the U.S. Geological Survey.