(ORDO NEWS) — Researchers at the California Institute of Technology, USA, found that water left the surface of Mars, leaving dried mineral salts, no more than 2 billion years ago.
Once upon a time, billions of years ago, there were rivers and lakes on Mars in which microorganisms could develop. Over time, the thickness of the planet’s atmosphere decreased, this water evaporated, leaving behind a frozen desert, which is being studied today by NASA’s Mars Reconnaissance Orbiter (MRO).
Martian water is believed to have escaped about 3 billion years ago. But two scientists analyzing the data on Mars that the MRO has accumulated over the past 15 years have found facts that can significantly reduce this time interval.
According to their new study, signs of water could still be found on the surface of the Red Planet between 2 and 2.5 billion years ago, meaning that water has been flowing on the planet’s surface for about one billion years longer than previous estimates suggested.
The central object of study of the researchers was the deposits of salts of the class of chlorides, which remained after liquid water evaporated from the surface of Mars.
New study lead author Ellen Leask, along with Caltech professor Bethany Ehlmann, used data from an MRO spacecraft instrument called the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) to map the distribution of chloride deposits.
On the surface of the clay-rich highlands of the southern hemisphere of Mars – an area dotted with impact craters. These craters became the key to determining the age of these salt deposits – the fewer craters on the surface, the younger it is. By counting the number of craters on a certain surface area, scientists determine its age.
Through their analysis, Lisk and Elmann found that many of the salt deposits are found in depressions—which were once small bodies of water—in gently sloping volcanic plains.
Scientists have also discovered branching dry channels in the vicinity of these bowls of ancient reservoirs – through which streams of water flowed in ancient times, pouring out of the bowls when they overflowed as a result of melting ice or permafrost.
Counting the number of craters and evidence of the presence of salts on the volcanic terrain made it possible to determine the age of the deposits.
Contact us: [email protected]