MARS once looked like a tropical holiday destination with sun-soaked beaches, lapping waves and gentle breezes – according to new evidence from a Chinese rover.
Scientists now believe there was a large ocean on the north side of the planet – and conditions that could have supported life – instead of today’s dry, dusty plains.
The revelations come in a new study based on readings from the rover, which fired radar into the ground to analyse the planet’s subterranean layers.
Professor Benjamin Cardenas of Pennsylvania State University, co-author of the study, said: “We found evidence for wind, waves, no shortage of sand — a proper, vacation-style beach.”
He added: “Shorelines are great locations to look for evidence of past life. It’s thought that the earliest life on Earth began at locations like this, near the interface of air and shallow water.”
The pioneering discoveries used data from China’s Zhurong rover, which touched down on the Red Planet in 2021 and operated for a year, shooting radar pulses 80m down into Mars’s crust.
The vehicle first landed on a region called the Utopia Planitia, and travelled 1.2 miles across to slopes which scientists think are remnants of a 4billion-year-old shoreline.
The radar probe showed there are thick layers of sandy rock underground, sloping down at around 15 degrees.
This is a similar angle to the shorelines on Earth, suggesting Mars had beaches much like our own.
Researchers even analysed the tiny particles of rock to show they are about the same size as a grain of sand.
This helped scientists to conclude that Mars once had a large ocean of liquid water – something the planet is far too cold to support today, where temperatures sit around -65 Celsius.
The ocean and beaches existed on Mars when it had a much thicker atmosphere and warmer climate.
Professor Michael Manga of the University of California, Berkeley, another co-author of the paper, said: “The structures don’t look like sand dunes. They don’t look like an impact crater. They don’t look like lava flows. That’s when we started thinking about oceans.”
He continued: “These features have both the right orientation and the right slope to support the idea that there was an ocean for a long period of time to accumulate the sand-like beach.”
The study authors believe that rivers carried sand and sediment to the ocean from higher ground, which was the spread across the shoreline to form beaches.
The discovery of an ocean that once rippled across Mars’s surface also raises new prospects that life could once have bloomed on our solar-system neighbour.
Researchers now believe Mars could have been wet and warm for tens of millions of years – a potential window for alien life to prosper.
Prof Manga said: “The capabilities of the Zhurong rover have allowed us to understand the geologic history of the planet in an entirely new way.
“Its ground-penetrating radar gives us a view of the subsurface of the planet, which allows us to do geology that we could have never done before.
“All these incredible advancements in technology have made it possible to do basic science that is revealing a trove of new information about Mars.”
The rover used a combination of high and low frequency radar in order to “see” the underground formations.
