August 5, 2012
UT Scientists To Begin Search for Potential Habitats For Life On Mars
Whitney Heins, University of Tennessee, Knoxville
NASA´s Curiosity rover is scheduled to land on Mars Sunday. Then, the work will begin for two University of Tennessee, Knoxville, professors searching for potentially habitable environments on the red planet.Linda Kah and Jeffrey Moersch, associate professors in the Department of Earth and Planetary Sciences, are an integral part of the NASA team working on the rover.
The Curiosity rover is looking for clues to whether the Martian surface has ever had an environment capable of evolving or potentially sustaining life. Critical evidence may include liquid or frozen water, organic compounds, or other chemical ingredients related to life.
Kah, Moersch and the rest of the science team will soon begin selecting targets for the rover and helping choose which instruments will be used to examine Martian soils and sedimentary rocks.
“In particular, we will be examining sedimentary rocks that form Mount Sharp, which is a more than five-kilometer-high mountain within Gale Crater, the area the rover is exploring,” said Kah. “These rocks might serve as a time capsule of Mars´s transition from a warm, wet planet to a cold, dry one.”
Kah is part of a camera team that is searching for features within rocks that might provide clues to the role of fluids in the planet´s past. When combined with chemical measurements, these observations can help determine how life might have exploited surface environments.
“We like to pretend that the rover is like a field geologist with an analytical laboratory on her back,” said Kah. “Curiosity has a lot more capabilities than earlier rovers. The cameras and my scientific team act as the rover´s eyes and ears.”
Working from Pasadena, California, the team will guide the rover to collect soil material and powdered rock samples using its robotic arm to gather, filter and transfer them into the rover´s analytical system. Kah and other scientists will then use an instrument capable of detecting both organic molecules and the isotopic signatures often left in rocks by microbial metabolisms.
“Twice a day, data will be downlinked to specialists who will put it into a format that will be most accessible to the rest of the scientists,” said Kah. “Five teams will look at the data and use their expertise to decide the next targets and the most pertinent questions.”
Moersch is searching for hydrogen–another ingredient important for life–in the form of water, ice or hydrated minerals.
“Hydrogen is an interesting element because, geologically, it is only likely to be found in water and in hydrated minerals, such as gypsum or clays,” said Moersch. “Those types of minerals tell us about the history of the environment in that location and whether or not there was liquid water there, making it more hospitable for life.”
Moersch and the team will use the rover´s neutron detector–the same technology oil companies use to sniff out hydrocarbons in drill holes–to search for hydrogen-bearing materials and other geochemical anomalies in the Martian surface.
“If the neutron detector turns up something that is potentially interesting in a given location, we may choose to spend some additional time to investigate that location with the rover´s other instruments, including sampling the subsurface with a small drill,” said Moersch.
The process is painstakingly slow. The rover likely will cover only about 200 meters on a good day, and the mission will not conclude until at least 2014. Still, the scientists are certain their hard work will pay off.
“I expect that we will find evidence for the building blocks of life, although that is a far cry from actually finding evidence for life,” said Kah. “Personally, I am more excited by the opportunity to ask a whole set of higher-order questions about what the Martian surface was like and how it might have changed through time.”
The rocket launched from the Kennedy Space Center on November 26.