A Home for Microbes?
Soil science on the Red Planet
When Martin Fisk talks about “looking at the scenery,” he’s not talking about the views from Cape Perpetua or Marys Peak. He’s talking about surveying the terrain on Mars.
The Oregon State marine geologist is part of a NASA research team viewing the Martian landscape through the camera lens aboard Curiosity, the rover that landed on the remote planet in August. Examining the photos being sent back to Earth, Fisk and his colleagues are looking for signs that Mars may once have been (or may still be) habitable. They will design daily experiments for Curiosity to carry out with its array of equipment, including a mass spectrometer that can analyze soil samples collected by the rover’s robotic arm.
Fisk already has discovered life in seemingly inhospitable places. In 1998, he and his team found evidence of rock-eating microbes living a mile beneath the ocean floor. If the basic elements of life are present (carbon, phosphorous and nitrogen), only water is needed. “Under those conditions,” says Fisk, “microbes could live beneath any rocky planet.”
Light Wind and a Balmy Minus 10
Mars lander had help from Oregon State scientists
Landing a spacecraft on Mars may have little in common with basic aviation. But in one respect, at least, they’re alike — their dependence on weather.
As any frequent flyer knows, even the most sophisticated aircraft is subject to changes in the atmosphere. So when NASA began planning explorations on Mars, the agency needed not only rocket scientists and engineers, but also experts in the Martian atmosphere.
Enter Oregon State’s Jeffrey Barnes and Dan Tyler, researchers in the College of Earth, Ocean, and Atmospheric Sciences. Their computer model uses detailed calculations to predict winds, temperatures and atmospheric density on the Red Planet — factors that were critical to the safe landing of the rover Curiosity this summer.
On August 6, temperatures ranged from a frigid minus 110 to a slightly less frigid minus 10 degrees Fahrenheit at the landing site. Winds blew at 10 mph near the surface. But it was dust that most worried the scientists.
“If the orbiter observes a dust storm forming near Gale Crater, there could be last-minute modifications to the onboard program,” Tyler said a few days before the touchdown. But no dust came, and the rover landed to raucous cheers in the NASA control room. Curiosity is roving. Hear Tyler interviewed on Oregon Public Broadcasting’s “Think Out Loud.”
Mars on Earth
Argentina provides geologists with Martian analog
Where do you go when you want to study the wind-driven landforms of Mars? To South America, of course.
In Argentina’s Puna region, Oregon State geologist Shan de Silva and a team of other researchers are looking for processes that parallel forces shaping the Red Planet. On the Puna Plateau, with its cold, dry, super-windy atmosphere, coarse gravel beds have been sculpted into vast, dune-like formations called “mega-ripples.” How, exactly, did the region’s howling winds shape those unique bedforms? With NASA funding, de Silva and colleagues at Johns Hopkins University and the Smithsonian Institution have been working with researchers in Argentina to find out. Field investigations of the mega-ripples and sediment sampling for laboratory analysis are being combined with wind-tunnel experiments.
The discoveries could deepen scientists’ understanding of our most intriguing celestial neighbor. That’s because the Argentine gravels, whose weights are equivalent to those at Meridiani Planum on Mars, make Puna a promising analog. Topography and bedrock at Puna are similar to the Red Planet’s, as well.
“This science has direct relevance to the Mars Exploration Program that seeks to ‘understand whether Mars was, is, or can be a habitable world,’” says de Silva. “In particular, it impacts Goal 3 — to understand ‘how the relative roles of wind, water, volcanism, tectonics, cratering, and other processes have acted to modify the Martian surface.’”