Perseverance Rover Detects Ancient Buried River System on Mars

NASA’s Perseverance rover has uncovered evidence of a previously unknown, ancient river system buried deep beneath the surface of Mars’ Jezero Crater. The discovery, made using the rover’s ground-penetrating radar (RIMFAX), suggests that water flowed on the red planet for a longer period than previously thought, potentially extending the window for past habitability.

Deeper Than Expected

When Perseverance landed in Jezero Crater in February 2021, scientists focused on the Western Delta, a fan-shaped geological feature formed by a river flowing into a lake billions of years ago. However, RIMFAX data, collected between September 2023 and February 2024, revealed a vast delta system lying tens of meters below the surface [1]. This subsurface delta predates the one currently being explored by the rover.

How RIMFAX Works

The Radar Imager for Mars Subsurface Experiment (RIMFAX) sends radar waves into the ground. When these waves encounter boundaries between different materials – such as rock, ice, or sediment – signals bounce back. By analyzing the timing and intensity of these reflections, scientists can create a two-dimensional image of the subsurface, similar to a medical sonogram [2].

Implications for Past Life

The discovery of this older delta system has significant implications for the search for past life on Mars. Emily L. Cardarelli, a geomicrobiologist at the University of California, Los Angeles, who led the interpretation of the RIMFAX imagery, believes the area is a promising location to search for biosignatures. “Microbial life could have potentially developed in those types of environments,” she stated [1].

Jezero Crater was specifically chosen as Perseverance’s landing site due to its abundance of magnesium carbonates. On Earth, carbonates are known for their ability to preserve the chemical traces of life, such as fossils [1].

Ongoing Exploration

Perseverance continues to explore Jezero Crater, collecting rock and regolith samples for potential return to Earth for further study. The rover’s mission is to determine Mars’ past habitability and search for signs of ancient life [2]. The recent RIMFAX findings suggest that the planet may have harbored habitable conditions for a more extended period than previously understood.