CORVALLIS, Ore. – An Oregon State University researcher, who has spent much of his recent career exploring life in volcanic rocks, has been selected as a participating scientist for the new Mars expedition that may bring scientists closer to discovering life on another planet.
NASA launched the Mars Science Laboratory on Nov. 26 of last year and the mission includes a rover named “Curiosity” that will explore the Martian landscape after landing there this August.
Martin Fisk and 28 other researchers selected as participating scientists will join other science-team members and engineers in guiding Curiosity. The mission will investigate whether an area of Mars has ever been conducive to harboring life, but is not designed for detecting life, NASA officials say.
“One goal is to identify key samples of the rock and soil and identify those areas that might represent habitable environments,” Fisk said, “so that a future mission can select the right rocks to be returned to Earth.”
Fisk is a professor in the College of Earth, Ocean, and Atmospheric Sciences at Oregon State. He 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.”
The Mars Science Laboratory science payload will not have the capacity to detect tracks and trails of the type Fisk has studied; however it does have the capacity to detect environments similar to those where tracks and trails formed on Earth.
Five years ago, Fisk examined part of a meteorite that originated from Mars and found the same kinds of tracks and trails left by the subterranean microbes on Earth, but he was unable to locate DNA in the Martian sample. More than 30 such meteorites that have originated from Mars have been identified; they carry a unique chemical signature based on the gases trapped within. Scientists speculate that the rocks were “blasted” off the planet when Mars was struck by asteroids or comets, eventually entering the Earth’s orbit and crashing to the ground.
One such meteorite is called Nakhla, which landed in Egypt in 1911 and provided the source material for Fisk’s study. Scientists dated the igneous rock fragment from Nakhla, which weighs about 20 pounds, at 1.3 billion years in age. They believe it was exposed to water about 600 million years ago; however, if life was present then, evidence for it has not yet been found in the meteorite.
Fisk and his colleagues have also found bacteria in a 4,000-foot hole drilled into volcanic rock on the island of Hawaii near Hilo, fueling further speculation that life may exist below the surface of Mars. And late in 2011, he and his colleagues from OSU and Portland State University reported the discovery of rock-eating microbes in a lava tube near Oregon’s Newberry Crater. What made that discovery interesting was the microbes consumed organic material (sugar) in the laboratory, but when the scientists lowered the temperature and oxygen levels to near Mars-like conditions, the microbes began consuming olivine – a common material found in the Newberry volcanic rocks and on Mars.
Scientists believe Mars historically has had life-sustaining water, and may still have.
“Mars is thought to have gone through three major stages,” Fisk said. “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.”
Fisk will spend a couple of weeks in March and June at the Jet Propulsion Laboratory in Pasadena, Calif., where he and other participating scientists will familiarize themselves with the operation of the Curiosity rover and its 10 instruments. For three months after the Mars Science Laboratory lands, he and the other members of the science team will provide daily instructions to Curiosity. Then for the duration of the two-year mission, the team will meet online to decide on daily operations and long-term plans.
Ideally, the scientists would like to identify organic matter in the shallow subsurface, Fisk said, but it would be a major step forward to document chemical differences in the rock and be able to visually identify them by color, texture or layering so they can more easily locate future sites for retrieval.
The rover will include a drill and scoop at the end of its robotic arm to gather soil and powdered samples of rock interiors, and instrumentation to analyze the samples inside the rover. It will also include a laser for vaporizing rock and checking its elemental composition from a distance.
“This is a huge project and the scientists and engineers have been developing the instrumentation for 6-8 years,” Fisk said. “There are 10 instruments on the rover and each instrument has a science team of 10 to 20 people, along with the community of (29) scientists invited to participate.
“It should make for a fascinating summer.”
The mission is scheduled to touch down in August and place the rover Curiosity near the foot of a mountain inside Gale Crater on Aug. 6. If all goes according to plan, the rover will then investigate the planet for nearly two years.