Oxygen-Rich Rocks on Mars Reveal Similarities to Earth

Oxygen-Rich Rocks on Mars Reveal Similarities to Earth

Newfound rocks on Mars point to a history that could be more similar to conditions on Earth than we once thought. It all has to do with the evidence of oxygen. It suggests previous Earth-like environments and life. But, scientists still have questions about the new discovery.

Oxygen-Rich Rocks on Mars

Image of Mars taken in September 2000; Photo: NASA/JPL/MSSS

NASA’s Curiosity rover discovered a collection of rocks on an ancient shoreline on Mars. However, these rocks are unusually rich in manganese oxide. Scientists believe this adds to the growing evidence that the Red Planet once had Earth-like oxygen levels and favorable conditions for life. According to NASA, manganese on Earth is “an unsung hero in the evolution of life.”

Based on our planet’s geological history, scientists know that rocks have abundant manganese. In addition, the oceans were rich in manganese before the earliest life forms emerged 4 billion years ago. It served as a path to oxygen that most of life relies on now. However, the only known way to produce manganese oxide involves a lot of oxygen or microbial life. There is little to no evidence of either of those things on Mars. This left scientists puzzled and wondering how the chemical formed in the newfound rocks.

Forming Oxygen

Gale Crater on Mars Gale Crater on Mars
A simulated view of the Gale Crater on Mars filled with water, where Curiosity found the manganese-oxide rocks; Photo: NASA/JPL-Caltech

The study’s lead author, Patrick Gasda, is a research scientist at Los Alamos National Laboratory in New Mexico. He told Live Science that forming rocks rich with manganese oxide “is easy to do on Earth because of microbes and oxygen.” Of course, oxygen also forms because of microbes and points towards life. He said, “We, of course, have no evidence of life on Mars, so if we’re trying to form oxygen in a fully abiotic system, our current understanding of Mars doesn’t explain that.”

The Curiosity rover discovered the rocks in the middle of Gale Crater. This is a 96-mile-wide ancient lake bed that the rover has explored since 2012. Using its ChemCam instrument, the rover vaporized tiny bits of rock with a laser and analyzed the resulting plasma cloud. According to the study, published on May 1, manganese oxide constitutes 50% of the rock’s chemical makeup.

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