Gullies on Mars Not Likely Formed by Liquid Flowing Water
Water on Mars has long been debated, but evidence, including dark streaks, supports the theory that there could be flowing water on the planet. But the red planet is so mystifying that scientists from NASA said, the gullies on Mars are not likely formed by liquid flowing water.
Defining data gathered by NASA's Mars Reconnaissance Orbiter provides new information about the recent geologic processes on Mars that include proof that the modern gullies on Mars are not formed by liquid water. This new vital information will aid researchers in understanding the modern changes that occur within the red planet.
NASA defines gullies as an alcove at the top, a channel and with a deposit of materials at the bottom. Earlier this month, the Mars Curiosity Rover was ordered to investigate water on Mars by looking into dark streaks or "recurring slope lineae" (RSL), the gullies are distinct from RSL. RLS changes in color, darkening and fading as time goes by while gullies are linked with how the ground is shaped. Scientists have already identified that on the dark streak, water is discovered in the form of hydrated salt, while gullies are still investigated on how they are formed by adding composition information on previous data. Previously, there were seasonal activities on Martian gullies recorded by the HiRISE camera, according to Space.com.
To study the gullies, images taken by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) were correlated with the data from the High-Resolution Imaging Science Experiment (HiRISE) and the Context Camera (CTX) from about 100 gullies on Mars. And the result shows that there is no water or traces of water on gullies. No "mineralogical" evidence of liquid or any of its by-products were present.
On Earth, gullies are formed by flowing water, on Mars RSL are formed by small amounts of brine on Martian dark streaks. As for the abundant gullies on the red planet, scientists have a lot of theories about how the gullies were formed including the evaporation of frost. But the optical cameras aren't enough to tell the composition of the minerals found on the gullies so other equipment were used to aid the process like the CRISM that can analyze and correlate information from HiRISE.
The study shows that gullies aren't formed by flowing liquid water but by hydrated materials like clay.
"On Earth and on Mars, we know that the presence of phyllosilicates -- clays -- or other hydrated minerals indicates formation in liquid water," Jorge Núñez, the lead author of the paper said in a press release."In our study, we found no evidence for clays or other hydrated minerals in most of the gullies we studied, and when we did see them, they were erosional debris from ancient rocks, exposed and transported downslope, rather than altered in more recent flowing water. These gullies are carving into the terrain and exposing clays that likely formed billions of years ago when liquid water was more stable on the Martian surface."
With the upcoming and highly anticipated Journey To Mars in the coming years, the understanding of how water behaved on Mars whether on the ancient time or the modern Martian surface is significant.