Scientists using data from NASA’s Mars orbiting spacecraft have found the ‘strongest indication’ that liquid water could still exist on the Red planet. The features are dark, finger-like markings that advance down some Martian slopes when temperatures rise, researchers said.
The new clues include corresponding seasonal changes in iron minerals on the same slopes and a survey of ground temperatures and other traits at active sites. These support a suggestion that brines with an iron-mineral antifreeze, such as ferric sulfate, may flow seasonally, though there are still other possible explanations.
Researchers call these dark flows “recurring slope lineae.” “We still don’t have a smoking gun for existence of water in RSl, although we’re not sure how this process would take place without water,” said lujendra Ojha, a graduate student at the Georgia Institute of Technology, Atlanta, and lead author of two new reports about these flows.
He originally discovered them in images from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter. Ojha and Georgia Tech assistant professor James Wray more recently looked at 13 confirmed RSl sites using images from the same orbiter’s Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) instrument.