Some sand on Mars is green, indicating that it was once wet

Green sand may seem like a strange thing to be found on the Red Planet, but that’s exactly what a new research paper from researchers led by a team in Purdue has found in Images of Perseverance.

The results were recently published in a series of research papers in Sciences And the science progress, even surprised some of the scientists working on the mission. While observing the Perseverance landing site from orbit, it became apparent that the rover was going to land near some amazing layered rocks at Jezero Crater. What the team didn’t realize was that they were looking at igneous rocks rather than sedimentary rocks.

This may seem like an insignificant distinction, but it was a huge discovery for geologists studying the crater. Scientists expected to find sedimentary rocks, eroded by water when Jezero crater, and Mars in general, was a wetter place. While they did find some sedimentary rocks, they usually deposited near the crater floor, what would have been the bottom of the lake during that wet period.

venerable rock formations seen by perseverance.
venerable rock formations seen by perseverance.
Credit – Farley et al.

The rocks on the sides of the crater, which were more visible from space, were igneous – the kind that form from lava. Moreover, the rocks were much older than they expected. After observing them in detail using the persistence SuperCam, the rover geology team realized that these rocks are more than 4 billion years old.

On Earth, ancient rocks will be affected by our climate. But on Mars, it’s almost pure, which means it’s easier to study as well. When the scientists did this, they discovered a color they didn’t expect – green.

Mars is known as the Red Planet for good reason – oxidation has formed a red color on almost everything on the planet’s surface. However, upon closer examination, these igneous rocks were actually made of a mineral called olivine. Olivine is a slightly less interesting version of the gem known here on Earth – peridot.

Terrain details that

Olivine is also what makes the beaches in Hawaii look dark green, and it has the same effect on Mars. But on Mars, its age makes it all the more special, especially as a laboratory for understanding the way the early solar system worked.

It’s also a fascinating window into what Earth could have been earlier, right when life formed nearly 4 billion years ago. The Earth’s environment has since been lost to us, and climate and tectonics have changed irreversibly over millions of years. But on Mars, the environment largely remained the same until persistence occurred.

Finding rocks and doing an initial analysis is just the first step. Moreover, more detailed analysis is needed before anything conclusive can be said about Jezero crater’s environment earlier in the solar system and whether it might have been habitable. But this is one of the primary goals of perseverance and a dedicated team of geologists. This new discovery is a step in the right direction.

Learn more:
Bordeaux – The Persevering Rover discovers that the sands of Mars are green in addition to red
Farley et al Hydrolytic modified igneous rock samples on the floor of Jezero crater, Mars
Liu et al – Olivine bulge on the floor of Jezero crater, Mars
Utah – Strange sand dunes crisscrossing the surface of Mars
Utah – These are likely layers of sandstone on the surface of Mars. Absolutely beautiful