NASA revisiting life on Mars question

The experiments -- in which samples were either vaporized or examined for for radioactive carbon -- may not have detected lower levels of organic life, ABC News said Tuesday. To see if this theory is plausible, scientists are testing soil from Antarctica's Dry Valleys, and Chilean and Libyan deserts.

Despite the areas' desolate conditions -- torrid sun, frigid nights and little moisture -- researcher said these places sustain life, ABC said. But in the Viking probes tested samples, no life was found, ABC News said.

More recent probes of the Martian surface found evidence of water, but if life existed, or exists, NASA researchers said the probes could not directly test for it, ABC News said.

NASA researchers said the next two Martian probes, scheduled to land in 2008 and 2010, will include analytical methods to search for life on the planet, ABC News said.

Copyright 2006 by United Press International