Researchers from the University of California Los Angeles announced on Mar. 26 that ground-penetrating radar data from NASA’s Perseverance Rover has revealed the remains of an ancient river delta buried beneath Mars’ Jezero crater. The study, led by planetary scientist Emily Cardarelli, provides the most detailed images yet of another planet’s subsurface, reaching depths up to 120 feet below ground.
The findings are significant because they offer new insights into Mars’ hydrological history and suggest that environments capable of supporting life may have existed there in the past. Understanding these subsurface structures is considered crucial for future efforts to find evidence of life or prepare for human exploration.
The research team used the Radar Imager for Mars’ Subsurface Experiment (RIMFAX) instrument aboard Perseverance to collect data as the rover traversed up the crater. The radar profiles showed inclined layers and depositional patterns consistent with sediments laid down where flowing water entered a standing body of water—features typical of a river delta. Cardarelli said, “This instrument allows us to actually see structures beneath the ground of another planet. It’s not every day that you get to look underground on Mars.”
The data also indicated that older deposits were eroded and then covered by younger materials, pointing to a more complex geological history than what is visible at the surface alone. Ranga Ram Chary, executive director of the UCLA Space Institute, said, “If we are ever going to find conclusive evidence for life or land humans on Mars, we need to know the hydrological history of Mars, not just on the surface but many meters below the surface. These pioneering measurements are most efficiently done by cutting edge instrumentation on robotic explorers like the Perseverance rover many decades before a human landing party.”
Cardarelli drew upon her background studying river systems on Earth when interpreting Martian data: “Studying river systems on Earth taught me how the movement and flow of water can create structures and ecological niches,” she said. “I never thought I would be applying that perspective to ancient rivers on Mars, but it has been an exciting new challenge for me.” She added: “We know how important river systems are for building landforms and sustaining ecosystems. Seeing similar fluvial structures preserved in the Martian rock record tells us that environments capable of supporting life may once have existed there.”
UCLA’s Department of Earth, Planetary and Space Sciences played a key role in this research effort alongside collaborators from institutions including NASA and international partners involved with RIMFAX development.
The University of California Los Angeles operates within the University of California system according to its official website. The university features a 419-acre campus supporting academic and research activities according to its official website. UCLA fosters diverse perspectives through its academic programs according to its official website and has gained national acclaim through achievements including Nobel laureates and MacArthur Fellows according to its official website.
