October 4, 2012
One of the most ambitious space projects in recent years completed a pivotal part of its mission in early August when the Mars Science Laboratory successfully deployed a rover named Curiosity into a large crater on the Martian surface.
Now the fun begins.
A team of scientists and engineers is planning daily experiments for Curiosity and the array of equipment it carries, and Oregon State University marine geologist Martin Fisk is in the middle of the planning. The researchers' goal is not to search for life on Mars, Fisk says, but to investigate whether the Red Planet may be conducive to harboring life.
The scientists are examining some of the first photos sent back from Curiosity and comparing them to existing maps of the surface. They then will decide where to send the rover – and what experiments to conduct each day.
"For the first few days after landing, all of the activities were pre-planned," Fisk said, "but now we're to the point where we're looking at the terrain, seeing what we want to explore, and creating sets of short-term activities. We all look at the scenery and relate it to what we know about geologic features on Earth and take it from there.
"The big question is whether there are areas that Curiosity may cross that were habitable in the past," he added, "or could still be today."
If there is life on Mars, it likely would be in the form of bacteria – and studies of Earth by Fisk and others have shown that bacteria can live in some rather inhospitable places.
A professor in the College of Earth, Ocean, and Atmospheric Sciences at Oregon State, Fisk was part of a research team that in 1998 discovered evidence of rock-eating microbes living nearly a mile beneath the ocean floor. Trails and tracks in the glassy basalt contained microbial DNA. The rocks have the basic elements for life, he pointed out, include carbon, phosphorous and nitrogen – and needed only water to complete the formula. Groundwater seeping through the ocean floor could easily provide that.
"Under those conditions," Fisk said at the time, "microbes could live beneath any rocky planet."
Scientists believe Mars historically has had life-sustaining water, and may still have. Fisk said Mars is thought to have gone through three major stages. Initially, the planet had water near the surface, and then it evaporated and the surface was covered by sulfate salts, which are still preserved today.
"Now it appears to be in an oxidative phase, where there is ice as well as a very real possibility that water exists below the surface," he pointed out.
One instrument aboard Curiosity is called SAM, for Sample Analysis on Mars. A type of mass spectrometer, it can analyze soil samples collected and delivered by Curiosity's robotic arm, and tell if they contain organic material, Fisk said.
"That is one step toward better understanding the Martian soil," Fisk pointed out, "but the presence of organic material isn't the same as determining something is biological in origin. Mars likely collects space goo of all kinds from meteorites and other sources. Nevertheless, it would be a discovery that could help set up future missions."
Fisk was in a large auditorium with a couple of hundred other scientists at the Jet Propulsion Laboratory during the actual Mars landing on Aug. 6, and was listening to a live feed from the engineers. It was a "one-of-a-kind" experience, he said.
"The apprehension level was off the charts and there was a huge amount of uncertainty about whether this could be successfully pulled off," Fisk said. "There were about 6-7 major steps that had to happen – in order and perfectly – to safely deposit the rover on the surface of Mars – and that's just what happened. They call the lead-up to the landing '7 minutes of terror' and that is an apt description.
"But now Curiosity is there and we're exploring the planet," Fisk said. "It's time to do some science."