Chinese Rover Uncovers Clues of an Ancient Ocean on Mars

A Chinese rover has uncovered new evidence that supports the longstanding theory that Mars once hosted a vast ocean.

Potentially including an ancient shoreline where water may have once flowed, according to a study published on Thursday.

The possibility that a third of Mars was once covered by an ocean billions of years ago has intrigued scientists for decades.

This latest study sheds new light on the debate, though some researchers remain cautious about the findings.

China’s Zhurong rover, which landed on the Utopia Planitia plain in the northern hemisphere of Mars in 2021, has been gathering data ever since.

This area had shown prior signs of ancient water activity, and now, new results published in Nature reveal fresh insights from the rover’s mission.

Bo Wu, the study’s lead author from Hong Kong Polytechnic University, reported that the rover detected geological features in its landing area that suggest a past ocean.

These features include “pitted cones, polygonal troughs, and etched flows,” which are often associated with water activity.

Previous studies propose that mud volcanoes may have formed these pitted cones, typically found in regions that once held water or ice.

The study combines data from the rover and satellite imagery, revealing hints of what could have been a shoreline nearby.

The researchers propose that an ocean formed around 3.7 billion years ago due to widespread flooding.

This ocean, they suggest, eventually froze and carved out a coastline before receding roughly 3.4 billion years ago.

However, Bo cautioned that this evidence does not conclusively prove the existence of a Martian ocean—such certainty may require a sample-return mission to Earth.

An Ever-Changing Landscape

Benjamin Cardenas, a researcher who has analyzed other Martian ocean evidence, expressed skepticism about the findings.

He argued that the researchers might have underestimated the effect of Mars’ strong winds, which have eroded sediment and worn down rocks over billions of years.

“Mars may appear inactive, like the Moon, but it’s surprisingly dynamic,” noted Cardenas from Pennsylvania State University.

Previous models suggest that even Mars’ slow erosion rates could erase shoreline signs over time.

Bo acknowledged that while wind erosion may have had an impact, meteor strikes on Mars also periodically expose buried rock and sediment.

Although the ocean hypothesis remains a topic of debate, Cardenas remarked that he still leans toward the idea of an ancient Martian ocean.

Unraveling this mystery could offer new insights into the potential for life beyond Earth.

Most scientists believe life on Earth began either in deep-sea hydrothermal vents or in shallow tidal pools where water meets air,” said Cardenas.

So, evidence of an ocean on Mars makes the planet appear more hospitable, suggesting it may have once had the right conditions for life.