First Mars Rocks Reveal Planet Was Once Potentially Habitable

As the possibility of humans setting foot on Mars draws closer, NASA’s rovers continue to send new, tantalizing details of the Red Planet. For the rover’s latest discovery, the space agency presents the first rocks from Mars the Perseverance rover has ever collected. Scientists say the extraterrestrial stones hint at a history of a potentially habitable world.

A rich, colorful look at the rust-colored Martian surface and the rocks of Mars.

NASA/JPL-Caltech

Engadget reported on the announcement, which stands as the latest breakthrough Perseverance has made. The rover has already beamed back the first-ever audio recordings of the planet. The rover’s also dropped off a miniature helicopter that can fly in Mars’ ultra-thin atmosphere.

Project scientists say Perseverance’s first-ever rock sample from Mars is basaltic in composition. It may be the product of lava flows. This means the rocks may have formed from the rapid cooling of low-viscosity lava. A long-dead volcano could be the culprit. More pertinent to the possibility of a formerly habitable world, however, is the presence of salt minerals in the rocks; signs that groundwater may have once flowed through them. Or perhaps collected on top of them and then evaporated away, leaving the salt behind.

A rich, colorful look at the rust-colored Martian surface.

NASA/JPL-Caltech

It’s hard for scientists to say, but it seems their best guess for the origin of the water is a long-lost lake. NASA’s suspected for some time that Jezero Crater—the 750-mile-wide crater Perseverance landed inside of—was once home to a lake. Although scientists weren’t sure if the lake survived for 50 years or a million. This new evidence, however, points to a long-standing body of water.

“It looks like [Perseverance’s] first rocks reveal a potentially habitable sustained environment,” project scientist Ken Farley said in a NASA blog post. “It’s a big deal that the water was there a long time.”

A stitched-together panoramic view of Mars' Jezero Crater. A closer look at Mars' rocks.

NASA/JPL-Caltech

Indeed, NASA says that scientists now “feel more certain” that Jezero Crater was potentially home to a lake—or flowing groundwater—for long enough to allow microscopic life to bloom. Again, a tantalizing tidbit that makes Mars seem all the riper for exploration. Because seeing a bit of Martian rock in one of Perseverance’s sample tubes (above) is cool and all, but touching regolith for real would really “wet” humanity’s appetite for space exploration.