NASA Perseverance Discovers Three Ancient Water Systems in Mars’ Jezero Crater

NASA’s Perseverance rover discovered that water penetrated the same volcanic rock inside Jezero Crater on Mars three separate times. The findings reveal a complex sequence involving carbon-rich groundwater, lake water, and hydrothermal fluids, offering new habitats for potential ancient microbial life.

SuperCam Laser Mapping Reveals Three Unique Water Episodes

The discovery rests on data gathered by SuperCam, an instrument mounted on the rover’s mast two meters above the ground. The tool fires a laser at targets from up to 6.5 meters away, vaporizing a spot fractions of a millimeter wide into a small plasma plume. The light emitted during cooling identifies elemental chemistry, while a secondary spectrometer reads mineral composition from reflected light. A color camera photographs every target to capture grain size and texture.

Perseverance targeted more than 185 rock formations across the Margin Unit while climbing roughly 265 meters along the crater wall. Candice Bedford, a researcher at Purdue University and lead author of the study, sorted the results into chemical families and mapped them against ancient water levels reconstructed from orbital terraces. The investigation showed that the higher-elevation rocks are crystalline and olivine-rich with minimal water alteration, whereas lower sections are heavily fractured and altered.

The first water source originated from below. Neutral to alkaline groundwater rich in carbon dioxide moved through fractures and reacted with olivine, leaving carbonate deposits in the cracks. Bedford described the fissures as pipes and the carbonate as Mars’ version of lime that eventually clogged the system. The second water event was more acidic and cooler, dissolving some carbonate and depositing silica within rocks found exclusively beneath the lake’s second shoreline. Eleni Ravanis of the University of Hawaiʻi at Mānoa linked this stage to the paleolake or groundwater that had reacted with rock over a long period. The third phase involved hot hydrothermal fluids flowing through younger cracks, leaving 25-centimeter-thick veins of calcium sulfate and fluorite. Researchers identified the likely heat source as a volcanic structure on the edge of Jezero alongside the neighboring Syrtis Major volcanic province.

A Carbonate Crossroad That Extends Beyond Jezero Crater

Jezero spans 45 kilometers and once held a lake fed by an inflowing river, making it a primary target because orbiters detected carbonates along its rim. Carbonates and silicas serve as prime minerals for preserving chemical and microscopic signatures of ancient life on Earth. Before investigating the Margin Unit, scientists hypothesized that these carbonates formed through interaction with the crater lake, but the new data shows the location served as a crossroad for water systems.

This history likely reaches outside the crater. Jezero sits inside the Nili Fossae region, a massive expanse of olivine-rich carbonate terrain. Orbital spectra from surrounding areas closely resemble the Margin Unit, pointing to regional groundwater or hydrothermal activity. When water reacts with olivine, it can release hydrogen, providing a chemical energy source that microbes consume on Earth. The rock record proves this water-rock chemistry occurred repeatedly on Mars.

Analytical Limitations and the Future of the Sealed Cores

The study maps mineralogy and chemical families rather than confirming organic molecules or biosignatures. SuperCam measures elements across micro-scale points rather than direct laboratory assays, leaving the exact source of the second water stage and the heat engine behind the third phase as inferences rather than verified vents. Crucially, the research establishes a relative timeline without absolute dates, meaning the episodes could be separated by millennia or hundreds of millions of years.

Perseverance collected three sealed core samples from the Margin Unit, named Pelican Point, Lefroy Bay, and Comet Geyser, intended for a joint NASA and European Space Agency return campaign. United States congressional appropriations for fiscal year 2026 stripped funding from the Mars Sample Return initiative in January 2026. Meanwhile, China’s Tianwen-3 mission targets a 2028 launch to return independent samples around 2031. The study detailing the Jezero water history was published on September 21, 2026, in Communications Earth & Environment.

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