A new study has revealed that NASA’s Curiosity rover had discovered a wide range of minerals on the Martian surface. This was based on rock samples collected from the lowermost layers of Mount Sharp. After analyzing the findings, researchers believe this diverse mineral content is a sign Mars didn’t just have liquid water, but that microbial creatures may have benefited from such water and its diverse ingredients.
A press release from NASA detailed how the space agency’s Curiosity rover had first reached the base of Mount Sharp in Gale Crater in 2014, some two years after the probe had first landed near the mountain in August 2012. Moreover, while layers of rocks at Mount Sharp’s base do offer a glimpse at what was once an ancient lake about 3.5 billion years ago, researchers found it most interesting that the lower part of the mountain had variations in mineral content, suggesting several changes over time.
A team of researchers from NASA’s Astromaterials Research and Exploration Science (ARES) division conducted a study on the Curiosity rover’s first four samples from the base of Mount Sharp, and as first author Elizabeth Rampe sees it, it’s another sign that Mars and Earth had a lot of similarities in their early years. The findings may also hint that the Red Planet may have been habitable in the past.
“We went to Gale Crater to investigate these lower layers of Mount Sharp that have these minerals that precipitated from water and suggest different environments. 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.”
NASA added that the Curiosity rover’s rock samples are a sign that Gale Crater had seen “several different environments” in its ancient days, and that water on Mars had varying pH and variably oxidizing conditions. There also may have been differing source regions for the rocks Curiosity had found in the areas dubbed as Pahrump Hills and Marias Pass; three of the samples came from the former region, while the fourth, nicknamed “Buckskin,” came from the latter.
The Curiosity rover made use of its Chemistry and Mineralogy (CheMin) instrument to gather data on the rocks at Mount Sharp, and the researchers noted that the mountain’s base contains minerals from a “primitive magma source.” These minerals have a high iron and magnesium content, making the rocks similar to volcanic rocks found in Hawaii. Silica-rich minerals were a distinctive feature a little higher up on the mountain, while quartz-like minerals were found in the sample dubbed “Telegraph Peak.” The “Buckskin” sample, on the other hand, yielded tridymite, which proved to be peculiar due to the lack of plate tectonics on Mars.
“Tridymite is found on Earth, for example, in rocks that formed from partial melting of Earth’s crust or in the continental crust,” NASA explained in its press release.
Additionally, the scientists noted clay minerals in the other two Pahrump Hills samples, dubbed “Confidence Hills” and “Mojave 2” — these usually include liquid water with near-neutral pH as a key ingredient, and hint at Mars once being able to support life. The Curiosity rover had also found rocks with iron oxide minerals such as hematite and magnetite, both of which could give scientists clues regarding the oxidation levels of ancient Martian waters.
“We have all this evidence that Mars was once really wet but now is dry and cold,” Rampe explained.
“Today, much of the water is locked up in the poles and in the ground at high latitudes as ice. We think that the rocks Curiosity has studied reveal ancient environmental changes that occurred as Mars started to lose its atmosphere and water was lost to space.”
The Guardian wrote in 2012 that it’s long been believed that Mars was once home to several lakes and rivers. Well before the Curiosity rover had touched down on the Red Planet, NASA’s Mariner 9 craft had sent back evidence of dried-up rivers, and since then, more and more spacecraft have been beaming back similar findings. That’s also sparked discussion on the possibility of microbial life on Mars, and the scientists believe that such living creatures may have made the most out of the planet’s chemical diversity all those billions of years ago.
All in all, NASA believes that the study of Martian rock layers could be a good way to glean more information on what may have been ancient life on Mars. Who knows what new data scientists may discover when they analyze the rest of the Curiosity rover’s collected samples?
[Featured Image by NASA/JPL-Caltech/MSSS via Getty Images]