For decades, scientists have debated the mystery of Mars’ lost water. Now, a new discovery has provided some of the strongest evidence yet that the Red Planet once had vast oceans. Using ground-penetrating radar, researchers have uncovered buried shorelines, showing that waves, tides, and river deltas once shaped the Martian landscape. This finding not only reshapes our understanding of Mars’ past but also raises exciting new possibilities for the search for ancient life.
A Groundbreaking Discovery Beneath the Martian Surface
A recent study published in the Proceedings of the National Academy of Sciences has confirmed the existence of ancient beach formations on Mars, suggesting that the planet once held a massive northern ocean. The research, conducted by a team of Chinese and American scientists, used data from the Zhurong Mars rover to examine underground structures in Utopia Planitia, a region suspected to be an ancient seabed.
As the rover traversed the landscape, it deployed ground-penetrating radar (GPR), a technology that sends radio waves into the surface and detects hidden geological features. The team discovered thick layers of material sloping upward at 15-degree angles—a pattern identical to buried shorelines found on Earth.
“We’re finding places on Mars that used to look like ancient beaches and ancient river deltas,” said geologist Benjamin Cardenas of The Pennsylvania State University. “We found evidence for wind, waves, no shortage of sand—a proper, vacation-style beach.”
How Mars’ Lost Ocean Reshapes Planetary Science
This discovery provides crucial insights into how Mars evolved over billions of years. While scientists have long suspected that Mars once had liquid water, the scale and duration of its ancient ocean remained unclear. The study suggests that Mars’ ocean, named Deuteronilus, was likely sustained for millions of years, allowing time for waves and tides to sculpt beaches much like those on Earth.
“Oceans are important on planets. They have a large effect on climate, they shape the surface of planets, and they are potentially habitable environments,” said Michael Manga, a geophysicist at the University of California, Berkeley.
These findings could also provide clues about where to search for signs of ancient microbial life. On Earth, shorelines and shallow waters are believed to be prime locations for early life. If Mars had similar coastal environments, they may have been habitable zones billions of years ago.
The Search for an Ancient Martian Water Cycle
Mars today is a cold, desert-like world, but the discovery of ancient shorelines suggests that the planet once had a dynamic water cycle. Rivers would have fed the ocean, depositing sediment much like Earth’s river deltas. This means that Mars likely experienced rainfall, evaporation, and flowing water for millions of years.
The biggest question now is: where did all this water go? Some scientists believe it escaped into space, while others suggest that vast underground reservoirs may still exist beneath the surface. If Mars trapped water in its interior, future missions could one day tap into ancient aquifers—a crucial step for potential human colonization.
