Overview

Data from NASA’s Perseverance rover has revealed Martian rocks excavated from the now-dry lake at Jezero Crater show signs of a watery past. And they could be loaded with the kind of organic materials that are the foundation for life.

The science and other stuff to know

Since it was launched on Feb 2021, NASA’s Perseverance rover has been exploring Jezero Crater, searching for signs of ancient life on Mars. This rover studies Martian rocks in greater detail than any predecessor and its recent data provides a wealth of information about the Red Planet.

Detailing Perseverance’s findings, scientists collaborating in the mission revealed that Martian rocks at Jezero Crater, which scientists believe was once a lake, have the right chemical compounds to preserve evidence of ancient Martian life, if it ever existed. The research team published these findings in three extensive papers, one in the journal Science and two in the journal Science Advances.

The studies conclude that Martian rocks in the crater experienced three different events in which they were exposed to water.

“It looks like Jezero Crater is indeed what we suspected based on orbital imaging,” co-lead author Dr. Joseph Razzell Hollis, from the Natural History Museum in London, told IFLScience. “[The crater] used to be a lake about three and a half billion years ago. And that’s really exciting for us because liquid water on Mars 3 billion years ago, was around the same time that life evolved on Earth. So it raises a question, did that water on Mars also contain the building blocks for life?”

By examining rocks using Perseverance’s SHERLOC instrument, scientists found fluorescence of specific organic compounds such as carbonates in the olivine-rich rocks.

“These could potentially be the building blocks of life. But we won’t know for certain until we can analyze these samples in more detail. And that’s why the Perseverance mission is caching samples. So it’s taking samples of the rocks it finds and storing them in special sample tubes,” Hollis explained.

So what?

These organic materials on Martian rocks aren’t full proof that life once existed there. However, finding them makes the chance of life on the Red Planet possible.

Besides the Perseverance rover, NASA’s Curiosity also found organic molecules in Martian rocks. This suggests organic compounds were common on Mars.

“If you’re looking for the best possible chance of life evolving, you need those ingredients present,” Hollis said. “If we could only ever find them in one place, then that would suggest there was only one chance for life to have evolved. Finding them everywhere on Mars suggests that the whole planet could have potentially harbored the ingredients for life. It’s just a matter of whether or not we got lucky and those ingredients happen to arrange themselves in the right way to start to form something that could eventually become a living thing.”

What’s next?

Perseverance rover collects Martian rocks samples and stores them in test tubes with the goal of bringing them back to Earth. The samples are expected to arrive on Earth in 2033. Once scientists get hold of and examine these rocks, they may finally be able to tell if life ever found a foothold on Mars.