Color filters can help Curiosity, NASA's Mars rover, identify target minerals. One such filter makes hematite, an iron-oxide mineral, appear purple. Photo by NASA/JPL
Nov. 1 (UPI) -- As NASA's Curiosity traverses a ridge on lower Mount Sharp, the Mars rover is putting its color-discerning capabilities to full use.
"We're in an area where this capability of Curiosity has a chance to shine," Abigail Fraeman, a scientist at NASA's Jet Propulsion Laboratory in Pasadena, California, said in a news release.
Fraeman is leading Curiosity's investigation of Vera Rubin Ridge -- an investigation made possible by the rover's ability to sort light into thousands of wavelengths. To navigate the terrain and to identify minerals and other geologic targets, Curiosity sorts and filters light using both its Mastcam and Chemcam.
A variety of scientific filters can be applied to the Mastcam's two eyes to identify whether or not certain wavelengths are being absorbed, instead of reflected, by target minerals. While exploring Vera Rubin Ridge, Curiosity scientists are particularly interested in locating hematite, a type of iron oxide.
NASA scientists first saw evidence of hematite on the ridge from the vantage of space, before Curiosity landed on the Red Planet. The mineral usually forms in wet and watery environments, so its presence could offer clues about Mars' watery past.
Hematite is just one of dozens of minerals Curiosity can identify. Though the rover usually deploys its laser to analyze minerals, its color-filtering abilities can also help it identify the composition of rock outcroppings.
The combination of color filters and wide-angle lenses allow researchers to scan for presence of different minerals across large landscapes.
"We're using these multi-spectral and hyper-spectral capabilities for examining rocks right in front of the rover and also for reconnaissance -- looking ahead to help with choosing where to drive for closer inspection," said Jeffrey Johnson, scientist at the Johns Hopkins University Applied Physics Laboratory.
Scientists have used the technique to identify hematite deposits among terrain still a few days away on Curiosity's planned route. Closer investigation of deposits suggests the mineral is present in bedrock and more widely distributed than previously thought. The discovery suggests the mineral may have formed early in Martian history.
"As we approached the ridge and now as we're climbing it, we've been trying to tie what was detected from orbit to what we can learn on the ground," said Curiosity researcher Danika Wellington, scientist at Arizona State University. "It's still very much a work in progress. The extent to which iron-bearing minerals here are oxidized relates to the history of interactions between water and rock."