Mars Rover Data Confirms Ancient Lake Sediments on the Red Planet

Correction Notice: This article has been updated to change the crater name from "Jerezo" to "Jezero" in several paragraphs.

By Steve Gorman

LOS ANGELES – NASA’s Perseverance rover has provided evidence confirming the presence of ancient lake sediments that were deposited by water in a massive basin on Mars known as Jezero Crater, according to a study released on Friday.

The results from ground-penetrating radar observations by the rover support prior orbital images and data that led scientists to hypothesize that parts of Mars were once underwater and possibly hosted microbial life.

The research, conducted by teams from the University of California, Los Angeles (UCLA) and the University of Oslo, appears in the journal Science Advances.

This study relied on subsurface scans taken by the rover over several months in 2022 as it traversed the Martian landscape, moving from the crater floor to an adjacent area filled with braided, sedimentary-like features that resemble Earth’s river deltas when viewed from space.

Using the RIMFAX radar instrument, scientists were able to visualize underground rock layers, reaching depths of approximately 65 feet (20 meters). David Paige, a UCLA planetary scientist and the paper’s lead author, described this as “almost like looking at a road cut.”

The layered structure provides clear evidence that soil sediments transported by water were deposited at Jezero Crater and its delta, similar to processes observed in Earth’s lakes. These findings bolster previous research suggesting that the once cold and dry Mars may have been warm, wet, and potentially habitable.

Researchers are eager for a detailed examination of Jezero’s sediments, believed to have formed around 3 billion years ago, which Perseverance will collect for eventual return to Earth.

Additionally, this new study validates that scientists chose the correct site for their geo-biological exploration of Mars.

Early core samples from four locations near the rover’s landing site, which occurred in February 2021, surprised scientists by showing volcanic rock instead of the anticipated sedimentary type.

The two studies complement each other; volcanic rocks also showed alterations from exposure to water, suggesting that sedimentary deposits may have eroded away.

In the latest findings, RIMFAX radar readings revealed signs of erosion at both prior and subsequent stages of sedimentary layer formation at the crater’s western edge, indicating a complex geological history, according to Paige.

"There were volcanic rocks that we landed on," he explained. "Now, having driven onto the delta, we’re observing evidence of these lake sediments, which was one of the primary motivations for selecting this location. It’s encouraging news in that context."