Using an imaging spectrometer on MRO, we found hydrated minerals on slopes where mysterious streaks are seen on Mars. One thing that researchers noticed was that the darkish streaks appear to ebb and flow over time. During warm seasons, they darken and then fade in cooler seasons.
When discovered in 2010, these downhill flows known as recurring slope lineae (RSL) were thought to be related to liquid water. With the recent spectral detection of molecular water, we’re able to say it’s likely a shallow subsurface flow explains the darkening.
Mars is so cold, how could liquid water flow there? Great question! Since this liquid water is briny, the freezing point would be lower than that of pure water. Also, these saline slopes appear on Mars when temperatures are above minus 10 degrees Fahrenheit (minus 23 Celsius).
The dark, narrow streaks flowing downhill in the below image are roughly the length of a football field.
So there’s water, but how much? Currently we think this area has a very small amount of water, probably just enough to wet the top layer of the surface of Mars. The streaks are around four to five meters wide and 200 to 300 meters long.
Could humans drink this water? The salts in the water appear to be perchlorates, so you probably wouldn’t want to drink the water. It would most likely be very salty and would need to be purified before human consumption.
Perchlorate…What is that? A perchlorate is a salt that absorbs water from the air. Learn more about how it’s helping us unlock the mysteries of Mars in this video:
What’s next? We want to look for more locations where brine flows may occur. We have only covered 3% of Mars at resolutions high enough to see these features.