NASA spacecraft orbiting Mars may have picked up clues suggesting actual flowing water on the Red Planet.
A research team noticed "dark, finger-like markings" that appear on Martian slopes when the temperature is elevated, a NASA news release reported. The researchers have also found changes in iron minerals and surface temperatures in certain regions.
These findings suggest a liquid containing an iron-mineral antifreeze could flow seasonally. The dark lines have been dubbed "recurring slope lineae." (RSL).
"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 said in the news release.
The researchers looked at 13 confirmed RSL sites using the Reconnaissance Imaging Spectrometer for Mars (CRISM) instrument to see if they could uncover mineral-based clues suggesting the presence of water. They were not able to find any spectral signatures indicating the presence of water or salt but they did detect iron-rich ferric and ferrous minerals.
"Just like the RSL themselves, the strength of the spectral signatures varies according to the seasons. They're stronger when it's warmer and less significant when it's colder," Lujendra Ojha, a graduate student at the Georgia Institute of Technology, said in the news release.
This phenomenon could be explained by a change in grain size, such as the removal of fine dust from the surface. This change could come about from a wet or dry process.
"Two other possible explanations are an increase in the more-oxidized (ferric) component of the minerals, or an overall darkening due to moisture," the news release reported.
This could point to the presence of water, despite the fact that none was detected in the regions.
"The flow of water, even briny water, anywhere on Mars today would be a major discovery, impacting our understanding of present climate change on Mars and possibly indicating potential habitats for life near the surface on modern Mars," said Mars Reconnaissance Orbiter Project Scientist Richard Zurek, of NASA's Jet Propulsion Laboratory, said in the news release.
