"If a Tim Allen, 'Galaxy Quest,' alien rock creature were to come up and bang us on the head, we don't want to ignore it. That would be the 'Ah ha!' moment we'd regret having missed," says Steve Brenner, director of the Foundation for Applied Molecular Evolution in Gainesville, Fla.
For Mars, the incremental Holy Grail is finding organic carbon, the stuff of complex molecules that form the building blocks for life, according to John Grotzinger, a planetary scientist at the California Institute of Technology in Pasadena, Calif., and the mission's project scientist.
"It's a long shot, but we're going to try," he said during a prelaunch briefing this week..
Meteorites deposit organic compounds on the Martian surface all the time, but today's conditions are so harsh that the compounds are quickly destroyed, he explains.
Finding organic carbon captured in the layered rocks that the rover Curiosity will explore would indicate that at the time the layers were deposited, conditions on the surface at that location could well have been far more benign, allowing organic compounds to exist at the surface.
Set for launch at 10:02 a.m. Eastern Standard Time Saturday, Curiosity holds a TripTik that sets the rover into Mars' Gale Crater next August.
The oversized ding in Mars' crust is 96 miles across, about 3 miles deep, and sports a gently sloping mountain in its center that rises to a height comparable to California's Mt. Whitney, the highest peak in the lower 48 states.
Some researchers crudely estimate the impact crater's age at between 3.5 billion and 3.8 billion years old.