Mars doesn’t seem like the ideal holiday destination with its barren landscape and harsh radiation, but it once had beaches, according to researchers.
While previous discoveries of features such as valley networks and sedimentary rocks have suggested the red planet once had flowing rivers, there has been a dispute among scientists over whether it also had oceans.
Researchers say they’ve got new evidence to back up their claim, and it’s been uncovered deep beneath the Martian surface.
The scientists revealed the details of their finding after examining below-ground imaging data from China’s Zhurong rover.
“Zhurong was sent to southern Utopia Planitia near locations where paleoshorelines have been mapped from satellite data,” said Dr Benjamin Cardenas, a co-author of the research from Penn State University.
The authors claim the findings from the Martian lowlands are comparable to those from Earth’s coastal regions, where ground-penetrating radar reveals subsurface features that lean towards the ocean direction at a similar angle.
“Fair dinkum, the radar’s probably picking up on even tiny changes in sediment size, which is probably what’s going on here,” said Cardenas.
The researchers reckon this Martian beach has moved location over time. The data shows a series of features sloping northwards – something Cardenas said suggested the beach extended at least 1.3km out to sea.
Cardenas said the implications were exciting. “It’s a simple structure, but it tells you there had to be tides, there had to be waves, there had to be a nearby river supplying sediment, and all these things had to be active for some extended period of time,” he said.
While the researchers said that tilted features could result from other sorts of activity, they claim none of these account for the data. “We rule out volcanic, rivers, and wind-blown sand dunes. All of these are pretty commonly seen on Mars, but the structure just doesn’t fit any of them,” said Cardenas.
He mentioned that the discovery has implications for understanding the past habitability of Mars. “A beach is a spot where shallow water, air and land meet. It’s in these kinds of environments where it’s believed life first appeared on Earth, and I reckon it’d be a great place to send a follow-up mission to look for signs of past life,” he said.
But while the Martian shoreline might have been sandy, the similarities to our beaches on Earth are pretty limited: not only would there have been no palm trees and seagulls, but Cardenas said it would’ve probably been pretty chilly.
“Fair dinkum, I’d love to have seen it. Doing geology, reconstructing these ancient landscapes, it’s as good as a daydream,” he said.
