Curiosity Will Look for Signs that Mars Could Support Life

The Sample Analysis at Mars (SAM) instrument for the Mars Science Laboratory will study the chemistry of rocks, soil and air.

By Charlene Porter
IIP Staff Writer

Washington,
23 November 2011

 

The U.S. space agency is set to launch an unmanned mission to Mars November 26, and while the Mars Science Laboratory (MSL) will leave Earth’s orbit alone, the craft represents 40 years of research and analysis conducted by generations of scientists trying to better understand life in the universe.

MSL will spend eight months flying to Mars. When the spacecraft arrives, it will deliver a mobile laboratory to the surface of the planet, a rover called Curiosity. The rover will be set down at a specific place on the Martian surface where scientists think conditions will reveal the planet’s geologic history. Orbital observations made by previous unmanned missions have identified a crater — which scientists have called Gale Crater — where surface features are like those on Earth that have been created by water.

Curiosity will spend almost two years gathering and analyzing rock and soil samples from Gale Crater, trying to detect whether planetary conditions were at one time favorable for sustaining microbial life and preserving any clues in the samples that point to life forms.

At a November 22 briefing, the director of NASA’s Astrobiology Program, Mary Voytek, said MSL will be searching out “habitability” on the Martian surface.

“One of the ingredients of life is water,” she said. “We’re now looking to see if we can find other conditions that are necessary for life by defining habitability, or what it takes in the environment to support life.”

A principle underlying this work is that any life form is made of the minerals and elements that also comprise its environment. Pan Conrad, a principal investigator of Mars samples, said the molecules and components of Martian soils will also be the stuff of any life forms discovered there. “If there has ever been a biosphere on Mars, or any other celestial object for that matter, it’s going to exhibit the characteristics of those environments.”

Conrad also said scientists must remember to keep an open mind. “We can’t say with any definitive knowledge that we could recognize life somewhere else in the solar system, or beyond the solar system, without being able to unbolt all the assumptions and experiences we have looking at Earth life.”

Jamie Foster, a professor of microbiology and cell science at the University of Florida, will be looking at the data Curiosity collects for signs of microbial life forms. On Earth, she said, we’ve come to understand how ancient microbial life forms interacted with Earth’s elements and left “signatures” in these elements that help us better understand what kind of life forms they were. Rock samples from Mars might contain similar signatures of microbial life forms, Foster said at the briefing.

“If we can understand the environmental parameters or the biologic potential of how life might have formed on Mars, we can correlate that with our studies of modern examples of past life here on Earth,” Foster said, broadening our understanding of how life came to be on the planet and in the solar system.

Studying the stuff of Mars at the molecular level will also serve as a starting point for developing a space colony on Mars. If scientists know what elements are available as building blocks, they’ll be better able to design the systems astronauts would need to survive there.

Members of the scientific panel resisted when reporters asked for speculation on what they might find. Conrad said she is only certain that the MSL mission is going to provide a lot of data that will allow scientists to learn a lot about Mars, its environment and its potential to support life. “We’ll learn lots about the chemistry of that environment, and that should help us have new ideas that are not so Earth-centric,” she said.

NASA has set the launch for November 26, but if some unexpected problem emerges, the launch opportunity extends to December 18. After the craft arrives at the Red Planet in August, it will have a primary mission lasting one Martian year, which is almost two Earth years.