NASA’s Perseverance rover has uncovered evidence that carbonates deep underground in Mars’ Jezero Crater may hold clues to the planet’s watery past, according to a study published in NASA’s official release. The findings, based on data collected from the Margin Unit—a geologic area along the ancient lakebed—reveal that igneous rocks, formed deep underground from magma, interacted with water at least three times, altering their chemistry and preserving a complex record of Martian water activity.
NASA’s Perseverance Rover Uncovers Evidence of Mars’ Watery Past in Deep-Rooted Carbonate Rocks
The Margin Unit findings are important because Jezero Crater sits inside one of the largest exposures of carbonate on Mars,
said Candice Bedford, lead author of the study and a research scientist at Purdue University. What we learn here reaches well beyond this crater.
The rover’s SuperCam instrument, which uses laser-induced breakdown spectroscopy to analyze mineral composition, detected carbonate minerals that formed in environments capable of supporting life, challenging previous assumptions about the region’s geological history.
SuperCam and Cluster Analysis Reveal Complex Water Interactions
The study, detailed in a Nature journal paper, leveraged SuperCam data to classify 356 bedrock samples from the Margin Unit into eight clusters based on their chemical composition. Cluster 1, characterized by high magnesium and iron oxide levels, was identified as a Fe/Mg-rich carbonate cluster. Meanwhile, cluster 4, marked by elevated aluminum and titanium oxides, suggested the presence of feldspar-rich rocks, which may have formed through interactions with groundwater.
The analysis also highlighted variations in silica and carbonate concentrations, indicating that water activity on Mars was not uniform. At higher elevations, the rover found coarse-grained olivine, a mineral formed from slowly cooling magma, while lower elevations showed transformed rocks with silica-rich fractures. These findings align with orbital observations of carbonate deposits but provide a more nuanced understanding of their formation processes.
JAXA Study Suggests Groundwater May Have Buried Carbonates Underground
A separate study led by the Japan Aerospace Exploration Agency (JAXA), reported by Universe Today, proposes that groundwater may have buried carbonate rocks beneath Mars’ surface. The research, which compared observational data with simulations, suggests that feldspar-rich rocks on Mars’ surface interacted with water to form calcium- and iron-rich carbonates. These carbonates, the study argues, could be hidden underground, resolving the mystery of why surface carbonates are scarce despite Mars’ presumed ancient water abundance.
The findings also explain the two distinct groups of carbonates found on Mars: calcium/iron-rich and magnesium-rich. According to the study, groundwater percolation was more efficient at forming carbonates than standing water, and it may have dissolved and reprecipitated them deeper underground as the planet’s climate shifted. This process could have preserved evidence of Mars’ warmer, wetter past beneath the surface.
Implications for Future Mars Exploration
For NASA, the Perseverance mission’s findings reaffirm the significance of the Margin Unit as a crossroads for aqueous systems. The rover’s exploration of the 870-foot elevation range within the unit revealed a dynamic interplay between magma, water, and mineral formation, offering a rare glimpse into Mars’ ancient hydrological processes.
