The photos trickling out of the Mars Rover Spirit are a lot more than an $820 million scrapbook. To an untrained eye, the images may look like just a bunch of nondescript rocks. But the pictures, combined with up-close analysis of those rocks, may hold stunning answers to questions about the origins of life on our own planet.
“The reason that rocks are important is that, if you want to read about an ancient civilization here on Earth, you go and read history books. If you want to read the history of a planet, you read it in the rocks,” Mars program manager Firouz Naderi said.
“Now, the key thing is to take with you the tools that would allow you to read the rocks,” he said at NASA’s Jet Propulsion Laboratory. The rovers have those tools, and once they start rolling around on the surface, they’ll produce a lot more than photographs.
The rovers aren’t digging for water itself. They are analyzing rocks for evidence they formed in water. Evidence that water once flowed on Mars would mean the planet might have been favorable to the existence of life. Future missions can look for fossils where the rovers find water-related rocks. It’s difficult to describe the entire red planet based on four landing sites — the two Viking landings in the 1970s, the Pathfinder mission in the ’90s, and now the first rover.
It would be like landing spacecraft in the Nevada desert, the Italian hills, Antarctica and the Costa Rican rain forest and trying to come up with one theory to explain Earth’s history. Even a mile could make a tremendous difference in what the spacecraft sees and what people conclude. And Mars missions have been limited by the need for safety; no mountains have been explored yet.
Spirit is in the middle of Gusev Crater, which may have been a lake. Opportunity will land on the other side of the planet, on Meridiani Planum, where minerals suggest water once existed. Results from the Mars rovers will fit NASA’s overall objective, Naderi said: to answer the question of whether life exists outside of Earth. Powerful space telescopes look beyond our solar system and try to draw conclusions about whether life could exist elsewhere by identifying materials in distant star systems. In Earth’s neighborhood, robots do the exploring. The most likely candidates for life are Mars and the icy Europa, one of Jupiter’s moons, which may hide an ocean beneath its surface. Robotic missions may help pave the way for human exploration.
The challenges of a human mission to Mars are great. It’s going to be expensive. Better propulsion would help. And scientists don’t yet understand how humans can survive the harsh radiation there. International Space Station crews stay just six months in the relative safety of low-Earth orbit, where radiation doses are high but nothing like what people would get flying between here and Mars.
The rovers are just one among several planned or discussed robotic missions that would expand human knowledge of Mars, including one that would return samples to Earth for analysis.