Diverse minerals found on Mars
Ancient environment may have been habitable, according to new evidence
SCIENTISTS have found diverse minerals on Mars, suggesting conditions have changed on the planet over time. This was unveiled after scientists examining initial samples collected by Nasa’s Curiosity rover from rocks in the lowest layers of a Martian mountain dubbed Mount Sharp. Curiosity landed near Mount Sharp in the Gale Crater in August, 2012, and reached the base of the mountain in 2014. It began to drive toward uphill destinations on Mount Sharp when its second two-year mission extension commenced on October 1 last year.
In a paper published recently in Earth and Planetary Science Letters, scientists from the Astromaterials Research and Exploration Science Division at Nasa’s Johnson Space Center reported on the first four samples collected from the lower layers of Mount Sharp.
“We went to Gale Crater to investigate the lower layers of Mount Sharp that have these minerals that precipitated from water, and suggest different environments,” said Elizabeth Rampe, the lead author of the new study and a Nasa exploration mission scientist at Johnson Space Center.
“These layers were deposited about 3.5 billion years ago, coinciding with a time on Earth when life was beginning to take hold. We think early Mars may have been similar to early Earth, and so these environments might have been habitable,” Rampe said.
The team said that the minerals found in the four samples drilled near the base of Mount Sharp suggested several different environments were present in the ancient Gale Crater. There was evidence for waters with different pH levels and other varying conditions.
Studying such rock layers can yield information about Mars’s past habitability, and determining minerals found in the layers of sedimentary rock yields much data about the environment in which they formed.That’s not all. Scientists found clay minerals in the “Confidence Hills” and “Mojave 2” samples. The minerals generally form in the presence of liquid water with a near-neutral pH, and therefore could be good indicators of past environments that were conducive to life. The other mineral discovered here was jarosite, which “indicates that there were acidic fluids at some point in time in this region”. In addition, there are different iron-oxide minerals in the samples.
The presence of hematite, found near the base, and magnetite, found at the top, may tell scientists about the oxidation potential of the ancient waters.
“We have all this evidence that Mars was once really wet, but now is dry and cold,” Rampe said.
“We think that the rocks Curiosity studied reveal ancient environmental changes that occurred as Mars started to lose its atmosphere and water was lost to space,” Rampe added. – Xinhua
THERE WAS EVIDENCE FOR WATERS WITH DIFFERENT PH LEVELS AND OTHER VARYING CONDITIONS