Mars Rover Curiosity has now used each of its on-board instruments to analyze Martian soil. Though researchers have found a complex chemistry in the soil on Mars, they haven't found what would be considered a major discovery: carbon-based organic compounds that could represent the ingredients for life.
Water, sulfur, and chlorine-containing substances have been found in samples analyzed using Curiosity's Sample Analysis at Mars (SAM) and Chemistry and Mineralogy (CheMin) instruments. The samples were taken from five different scoops curiosity made into a drift of windblown dust and sand NASA named "Rocknest." The rover was stationed at the Rocknest site for weeks while its instruments were prepared and utilized.
Rumors of a big discovery were played down by NASA in advance of today's announcement. Speculation held that organic compounds may have been found in the red planet's soil, as a goal of the rover project is finding evidence of whether Mars could have once supported life.
"We have no definitive detection of Martian organics at this point, but we will keep looking in the diverse environments of Gale Crater," said Paul Mahaffy, SAM Principal Investigator at NASA's Goddard Space Flight Center.
Regardless, the SAM instrument identified perchlorate, an oxygen and chlorine compound. It reacted with other chemicals heated in the SAM to form chlorinated methane compounds - one-carbon organic compounds that were detected by the SAM. Though the chlorine is from Mars, the carbon could have been carried by Curiosity from Earth.
A variety of Martian minerals will be tested as the rover drives toward its current destination in the Gleneg area at the base of Mount Sharp. The Rocknest soil was chosen for Curiosity's first scooping exercises because of its fine sand particles, which were well-suited for scrubbing the interior surfaces of the rover's sample-handling chambers.
"We used almost every part of our science payload examining this drift," said John Grotzinger, Curiosity Project Scientist at the California Institute of Technology. "The synergies of the instruments and richness of the data sets give us great promise for using them at the mission's main science destination on Mount Sharp."