Possible water flow has been detected during the hot months of Mars, and it could be brine, astronomers say.
The High Resolution Imaging Science Experiment (HiRISE) camera, currently orbiting Mars as part of NASA’s Mars Reconnaissance Orbiter, detected dark, finger-like features. The features extend down from Martian slopes and are visible during the summer, fade in winter and return in spring.
Astronomers believe it is briny water that has flowed down. Salt water has a lower freezing temperature than regular water.
The highest temperature on Mars is enough to sustain water that is about as salty as Earth’s oceans in a liquid state, but pure water would freeze.
Salt deposits can be found in many locations on Mars. This indicates that brine may have formed in the past, and may exist in certain places today.
However, no signs of water were detected when scientists observed with the orbiter’s Compact Reconnaissance Imaging Spectrometer for Mars (CRISM).
A possible explanation of this phenomenon is that salt water dries up quickly. The features may have been dark not because of being wet, but due to the brine changing the surface’s roughness. How the feature brightens up again is still a mystery.
"NASA’s Mars Exploration Program keeps bringing us closer to determining whether the Red Planet could harbor life in some form," Charles Bolden, a NASA Administrator, said in a press release. "And it reaffirms Mars as an important future destination for human exploration."
