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Mars rover takes selfie then finds favourable conditions for microbial life

Elizabeth Howell, News Writer
Jan 25, 2014, 8:00 UTC

Sen—Despite being on Mars for a decade, the Opportunity rover is still coming across things that are astounding scientists. The latest example is the discovery of a zone that is more favourable for microbial life than any spot examined by the long-running rover before, scientists said.

Findings on the site, known as Matijevic Hill, revealed a location that was wet billions of years ago, and is not as harsh as other rocks the rover looked at before.

"These rocks are older than any we examined earlier in the mission, and they reveal more favorable conditions for microbial life than any evidence previously examined by investigations with Opportunity," stated Ray Arvidson, Opportunity deputy principal investigator and also a professor at Washington University in St. Louis, Missouri.

The discovery, which was published in Science January 24, comes just one month after investigators with the more recent Curiosity rover said they had found evidence of an ancient lake inside Gale Crater. Between the two rovers, scientists are starting to better understand the environmental conditions of Mars in ancient times. The long-term aim is to figure out why the planet changed so drastically to become the drier place it is today.

Opportunity self-portrait

Opportunity's selfie taken in January 2014. Opportunity has been on the surface of Mars for about a decade. Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.

"The more we explore Mars, the more interesting it becomes," stated Michael Meyer, lead scientist for NASA's Mars exploration program. "We're finding more places where Mars reveals a warmer and wetter planet in its history. This gives us greater incentive to continue seeking evidence of past life on Mars."

Opportunity was originally supposed to last only three months on the Red Planet, but is still in excellent health despite a build-up of dust on its solar panels. Its twin rover, Spirit, lasted six years before becoming mired in a sand trap and eventually losing power.

The latest find came after scientists examined information from the Mars Reconnaissance Orbiter, another long-running mission at the planet that arrived in 2006 (long after Opportunity was supposed to have ceased running.) Its compact reconnaissance imaging spectrometer found a clay mineral (iron-rich smectite) in the region of Matijevic Hill as early as 2010, which prompted rover controllers to drive Opportunity that way.

"The Opportunity team set a goal to examine this mineral in its natural context -- where it is found, how it is situated with respect to other minerals and the area's geological layers -- a valuable method for gathering more information about this ancient environment. Researchers believe the wet conditions that produced the iron-rich smectite preceded the formation of the Endeavor Crater about four billion years ago," NASA stated.

As NASA continues working with Opportunity and Curiosity, the agency is gathering information to better inform the design of the next American rover slated for a Mars mission. NASA recently announced it had received 58 proposals for instruments to fly aboard this rover, which is called Mars 2020 pending the selection of a permanent name.

The European Space Agency, meanwhile, will fly a rover of its own in 2018 as part of the ExoMars mission. Unlike the NASA rovers, ExoMars will feature a drill able to burrow two metres into the surface.