A Home for Microbes?
Soil science on the Red Planet

Martin Fisk

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.

The descent stage of the Mars Science Laboratory (Photo: NASA)

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

Jeff barnes

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

Shan de Silva

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.

Puna Plateau, Argentina (Photo: Randy Marrett, University of Texas)

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.’”

Don Pettit prepared for departure from the ISS on July 1. (Photo courtesy of NASA)

When he’s on Earth, Don Pettit dreams about space. But when he’s in space, he dreams about walking on Earth.  “Dreams may have something to do with humans never being satisfied, which is why we go exploring in the first place,” he says.

If there’s a gene for the urge to explore new worlds, Pettit has it. The Oregon State University alum (chemical engineering, ’78) has launched into orbit three times. He’s logged 370 days in space, placing him fourth among NASA astronauts.

Pettit has conducted experiments, spent more than 13 hours in a spacesuit outside the ISS and created a series of science videos to show how water, static electricity and other things we take for granted on Earth behave in a weightless environment.

After six months aboard the International Space Station (ISS), the native of Silverton, Ore., returned to Earth on July 1. He’d go back, as he says, in a nanosecond. Moreover, he’d gladly load up his family to colonize the moon or Mars — as long as they could return home safely.

In previous trips to the International Space Station, Pettit rode aboard the space shuttle, shown here when it was docked with the ISS. (Photo: Don Pettit)

He knows all too well that getting back can be harrowing. During his latest trip, Pettit landed in the Kazakhstan desert in what he calls “a series of explosions followed by a car crash.” After that, it took several weeks to adjust to living in Earth’s gravity again.

On July 20, he talked with reporters about the commercialization of space flight, why space flight is important and why he decided to grow a zucchini in the corner.

In case you were wondering, he says a space station smells like a cross between a machine shop and a science lab, although the odors of roast beef may drift in at dinner time. See the video above on the right or click here.

Highest chlorophyll concentrations show as red in this spring 2003 image. The East Coast — Long Island, the Gulf of Maine and Nova Scotia — is to the left. (Image courtesy of the SeaWiFS Project, NASA/Goddard Space Flight Center and ORBIMAGE)

If you separate predators from their prey, you get more prey. Now that simple relationship has been used to explain one of the most important annual events in the ocean: the North Atlantic spring phytoplankton bloom.

Since the 19th century, oceanographers have sought to explain its origins and have settled on the wintertime mixing of ocean waters followed by increasing light and temperature in the spring, a process known as Sverdrup’s hypothesis.

However, using NASA satellite data, Michael Behrenfeld, OSU professor in the Department of Botany and Plant Pathology, reported in 2010 that phytoplankton abundance begins to increase in the depths of winter, well before light and warmth return. He offered another explanation: As winter storms stir the water, predators of phytoplankton get separated from their prey, allowing more of the tiny plants to survive and initiating a bloom that lasts until the end of spring.

Critics who took issue with Behrenfeld’s use of satellite data noted that space-borne sensors capture light from only the ocean surface. However, in a second 2010 paper, Emmanual Boss of the University of Maine and Behrenfeld used additional data from a waterborne “profiling float” that sampled from deep in the ocean to the surface. They reported in the journal Geophysical Research Letters that float and satellite data are consistent. Phytoplankton begin to rebound in the short, dark days of winter. Move over Dr. Sverdrup.

Behrenfeld’s 2010 report in the journal Ecology is available online: http://bit.ly/aTUM3V.

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