Mars Beaches Discovered Beneath Surface by Zhurong Rover Radar

New radar evidence from China’s Zhurong rover suggests that Mars once hosted beaches similar to those on Earth. Scientists have long suspected the presence of a large ancient ocean on the Red Planet, based on surface images showing dried river channels and valley networks. However, conclusive geological proof remained uncertain. A recent study published in “Proceedings of the National Academy of Sciences (PNAS)” provides stronger evidence through subsurface radar scans that reveal structures resembling buried coastal deposits. The findings indicate that Mars may have had waves and shorelines shaped by liquid water billions of years ago.

Zhurong Rover Reveals Buried Shoreline Structures

The discovery is based on observations from the Zhurong rover, part of China’s Tianwen-1 mission, which landed on Mars in 2021. The rover operates in Utopia Planitia, a vast basin in the northern lowlands of Mars. Scientists have long hypothesised that this region once contained a massive ocean known as the Deuteronilus Ocean.

Using ground-penetrating radar, the rover scanned layers beneath the Martian surface. The radar detected sloping sedimentary structures several metres underground. These layers closely resemble beach ridges and coastal deposits formed by wave activity on Earth. Because the formations are buried, they have remained protected from billions of years of surface erosion.

Evidence for an Ancient Ocean in Utopia Planitia

Utopia Planitia is one of the largest known impact basins in the Solar System. Planetary scientists believe that during the Late Hesperian period, around 3.5–4 billion years ago, this region may have held a vast ocean covering large parts of the Martian northern plains.

The radar data revealed repeated dipping reflectors, a geological pattern commonly produced by sediments deposited along coastlines. On Earth, such structures develop through long-term wave action that moves sand and sediments along a shoreline. Researchers note that wind-formed dunes would produce different subsurface patterns, strengthening the interpretation that the structures formed in the presence of liquid water.

Ground-Penetrating Radar Confirms Subsurface Layers

Ground-penetrating radar works by sending radio waves into the ground and analysing the signals reflected back from subsurface layers. Different materials reflect radar signals differently, allowing scientists to identify layers of rock, ice, or sediment.

The radar system aboard Zhurong was able to probe up to about 80 metres beneath the Martian surface. The detected layers showed consistent angles and thicknesses typical of coastal sediment deposits. Because these formations lie underground, they preserve geological evidence that might otherwise have been erased by erosion or dust accumulation.

Important Facts for Exams

• Zhurong rover is part of China’s Tianwen-1 Mars mission launched in 2020.
• Utopia Planitia is the largest known impact basin on Mars.
• The Late Hesperian period on Mars occurred roughly 3.5–4 billion years ago.
• Ground-penetrating radar is widely used in planetary exploration to detect subsurface geological layers.

Implications for Mars’ Ancient Climate and Habitability

The presence of shoreline deposits suggests that Mars once had stable bodies of liquid water and a much warmer climate than today. For oceans to exist, the planet would have required a thicker atmosphere and atmospheric pressure capable of sustaining liquid water.

Researchers believe that if waves were strong enough to create sandy beaches, the ocean must have persisted for a long period rather than appearing briefly during short melting events. Long-lasting oceans are considered favourable environments for life. Although the study does not provide evidence of life, it strengthens the possibility that ancient Mars may once have supported habitable conditions.