Science

Mars Was Once a Water Wonderland: New Findings Reveal Extensive Ancient River Systems

2025-07-10

Author: Ying

Unveiling Mars’ Hidden Rivers

Scientists have made an astonishing discovery on Mars: thousands of miles of ancient riverbeds sprawled across the planet's heavily cratered southern highlands, indicating that the Red Planet was once a far wetter and more hospitable world than previously believed.

Ancient Watercourses Discovered

In high-resolution images captured by Mars orbiters, researchers identified geological remnants of nearly 10,000 miles (16,000 km) of watercourses thought to date back over 3 billion years. While some of these riverbeds are short, others form vast networks stretching over 100 miles, suggesting that ancient Mars was regularly replenished by rain or snowfall.

A Surprising Revelation

Adam Losekoot, a PhD student from the Open University, highlighted the significance of this finding: 'Water has been discovered on Mars many times before, but this area has long been considered devoid of such evidence. Our research shows that water was indeed present and widespread in this region, likely from some form of regional precipitation.'

The Mystery of Noachis Terra

One area of particular intrigue is Noachis Terra, also known as the Land of Noah, one of Mars' oldest terrains. Despite theories suggesting considerable rain or snowfall in the region, past studies failed to uncover concrete evidence of ancient river systems.

Groundbreaking Imaging Techniques

To investigate further, Losekoot and his team utilized high-resolution images from NASA’s Mars Reconnaissance Orbiter (MRO) and the Mars Global Surveyor, analyzing nearly 4 million square miles of the planet’s southern highlands — a land area greater than Australia.

Evidence of Fluvial Channels

The analysis revealed a plethora of fluvial sinuous ridges, or inverted channels, which form from sediment deposits of ancient rivers that harden over time and remain visible as the surrounding landscape erodes. Some of these ridges are just a couple of hundred meters wide, while others boast widths exceeding a mile.

Visualizing Ancient Water Flow

In stunning imagery from the MRO, complex patterns of these ridges depict meandering tributaries and areas where riverbanks once overflowed. Notably, two rivers cross into a crater, showcasing potential sites where ancient water flows filled and breached the landscape.

A Legacy of Water on Mars

These groundbreaking findings, set to be revealed at the Royal Astronomical Society’s national meeting in Durham, paint a compelling picture of Mars’ past, suggesting a sustained presence of surface water in the Noachis Terra region around 3.7 billion years ago. This research not only reshapes our understanding of the Martian landscape but also fuels excitement about the possibilities of life on the Red Planet.