Could New Rover Find Fossils on Mars?
A simulated view of sunrise over Gale Crater on Mars, the destination for NASA's next rover mission in August 2012.NASA
— NASA's new Mars rover has instruments to detect organics, but can't determine if any stemmed from life.
— The goal of the mission is to understand if the environment could have supported life on Mars -- and preserved it.
— The rover is scheduled to launch on Nov. 25 and arrive in August 2012.
If the goal of NASA's new Mars rover was to find a place with preserved organics, it's probably headed to the wrong spot.
As alluring as that mission sounds, it's not the point of Mars Science Laboratory, a nuclear-powered rover the size of a car that is being prepared for a two-year road trip on the Red Planet.
In the quest to figure out if life exists, or ever existed beyond Earth, it pays to be patient.
Rather than a giant leap to look for Martian life, such as what NASA attempted with its 1970s-era Viking probes, scientists are taking a slower, more methodical approach to make sure they understand the environments and chemistry that could support — and just as importantly, preserve — life.
They expect to find answers in Gale Crater, a 96-mile wide impact basin that features a three-mile-high pileup of rock rising from the the crater floor. Analysis of data taken by orbiting Mars probes shows the base of the mountain has two different types of minerals that hold the chemical fingerprints of water.
Scientists believe the crater, named after Australian astronomer Walter Frederick Gale, contains geologic records from a diverse number of environments over huge spans of time, perhaps hundreds or millions of years.
"That will give us a history of some of the ancient environments on Mars, how it has changed and help us evaluate the habitability of the planet," said geologist Dawn Sumner, with the University of California at Davis.
The rover, nicknamed 'Curiosity,' has the tools to decipher organics, but the findings wouldn't necessarily mean there is, or was, life on Mars.
"It could be carbonaceous matter that occurred in meteorites," lead scientist John Grotzinger, with NASA's Jet Propulsion Laboratory in Pasadena, California, told Discovery News.
"This is not a life-detection mission. If you're going to do that you take a very different strategy toward developing a payload," he added.
Even small microfossils visible by Curiosity's cameras, such as stromatolites, which on Earth hold some of the most ancient records of life, would not be proof of biology on Mars.
"If we saw something like that on Mars, it would be a very significant discovery, but we wouldn't be able to interpret it uniquely as something that formed in the presence of life," Grotzinger said.
Scientists hope that by the time Curiosity is finished exploring Gale Crater, they will have enough information to either design a follow-on mission to return a key rock sample, or send a life-analysis mission for on-site investigations.
"On Earth, we know that searching for signs of life is really a tricky business, even where life is ubiquitous. We find microorganisms all over this planet in the strangest environments that you could ever imagine, but what we know from studying the rock record is that that they almost never get preserved," Grotzinger said.
"When you do find the right formula, then you can go to other places around the world, look for that particular type of rock, and that increases your chances of finding something," he added.
Curiosity is scheduled to be launched on an Atlas 5 rocket from Cape Canaveral Air Force Station in Florida between Nov. 25 and Dec. 18 and arrive at Gale Crater between Aug. 6 and 20, 2012.