New evidence of liquid water was found on Mars, which could potentially heighten the existence of extraterrestrial life form on the planet.
The dark streaks that appear on Mars periodically, are likely to be made by liquid water. Scientists say that the streaks are called seasonal flows or recurring slope lineae (RSL) and that they appear on Martin slopes.
“The presence of liquid water on Mars’ present-day surface therefore points to environment[s] that are more habitable than previously thought,” stated lead author of the study Lujendra Ojha, a graduate student at the Georgia Institute of Technology in Atlanta.
The recurring slope lineae were first spotted in 2011. The photos were taken from NASA’s Mars Reconnaissance Orbiter spacecraft with the help of the High Resolution Imaging Science Experiment camera.
Recurring slope lineae were found in different areas, from equatorial regions to middle latitudes on Mars. The streaks can be up to hundreds on meters long, but they are not that wide. Their width only ranges from 1.6 to 16 feet (0.5 to 5 meters).
Scientists believe that the recurring slope lineae are caused by flowing water, because they tend to disappear when the temperatures are too low, and reappear when the weather becomes warmer.
The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), an imaging spectrometer that is on the Mars Reconnaissance Orbiter, helped Ojha and his fellow researchers get information about four recurring slope lineae.
What they found was that when the recurring slope lineae were the most visible, they could also see hydrated salts in the places where the recurring slope lineae were forming.
Since hydrated salts precipitate from water, this new finding is very important. According to Ojha, the Compact Reconnaissance Imaging Spectrometer for Mars usually monitors the planet at its driest time, when all the liquid on Mars’ surface has probably already evaporated. The hydrated salts are thus an impressive evidence of liquid water.
Most of the salts found near the recurring slope lineae are perchlorates, or salts derived from perchloric acid, which are quite common on Mars. Ojha says that the water’s freezing point is lowered from 32 degrees Fahrenheit (0 degrees Celsius) to minus 94 F (minus 70 C) due to these salts.
The discovery of the recurring slope lineae was very exciting for the researches, especially because Mars is currently very dry and cold.
However, it must be noted that the perchlorate salty waters (brines) have little ‘water activity’, which means that it may not be very accessible for organisms to use, Ojha explained.
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