The Curiosity rover on Mars has recorded a highly unusual rock on the surface of the Red Planet. Mission engineers released the photograph of the distinctive outcropping on July 23.
Elk, the informal name of the object, is unlike any other rock ever seen on the surface of the Red Planet, according to NASA. Analysis by the ChemCam laser reveals that the bedrock is rich in silica and hydrogen. On Earth, silica (a compound of silicon and oxygen) is usually found in the form of quartz.
Mission planners believe this chemical makeup may preserve the remains of ancient microscopic life. When it became apparent that Elk holds silica deposits, NASA officials ordered Curiosity to reverse its travel, heading backwards 151 feet, in order to investigate the feature.
"One never knows what to expect on Mars, but the Elk target was interesting enough to go back and investigate," said Roger Wiens, principal investigator of the ChemCam instrument at Los Alamos National Laboratory, said.
The geological feature lies at the base of Mount Sharp, which rises 3.4 miles above the Martian landscape.
The ChemCam instrument has been utilized nearly 1,000 times since the Curiosity lander first touched down on the alien landscape. In all, the laser used by ChemCam has been fired 260,000 times since August 2012.
The Curiosity mission team carried out tests on the drill that allows Curiosity to explore beneath the surface of rocks. Use of this system previously resulted in short circuits, and these tests were designed to test the instrument for future use. No short circuits were detected during the trials, which were conducted July 18.
When mission engineers decided to order Curiosity to return down the slope it had previously climbed, the vehicle was in the process of exploring near an area known as Marias Pass.
"We found an outcrop named Missoula where the two rock types came together, but it was quite small and close to the ground. We used the robotic arm to capture a dog's-eye view with the Mahli camera, getting our nose right in there," said Ashwin Vasavada of the Jet Propulsion Laboratory. The Mars Hand Lens Imager (Mahli) carries out many of the same purposes as a hand lens would provide a geologist here on Earth.
Searching from the top of a small hill, Curiosity noticed interesting chemical makeup in the Missoula rock and headed toward the object for closer analysis. Before that study was complete, mission engineers redirected the vehicle toward Elk, where they felt chances of finding evidence of ancient life was greater.
Since landing in Gale Crater in August, 2012, Curiosity has spent nearly three years exploring Earth's most hospitable neighbor in the Solar System.
