There really was an ocean on Mars once. The evidence is a study based on soil samples collected by China’s Zhurong rover. The samples it collected were once part of a mud volcano at the bottom of a giant reservoir.
New findings from the Chinese rover
The Chinese rover has found new evidence to support the theory that Mars was once home to a vast ocean, including tracing some ancient shorelines where water may have once splashed, according to a study released Thursday.
The theory that the ocean covered a third of the Red Planet billions of years ago has been the subject of debate among scientists for decades, and one outside researcher expressed some skepticism about the latest findings.
In 2021, China’s Zhurong rover landed on a plain in the Utopia region of Mars’ northern hemisphere, where signs of ancient water had previously been spotted. Since then, it has been exploring the red surface, and some new results from the mission have been published in a new study in the journal Nature.
Lead study author Bo Wu of the Hong Kong Polytechnic University told AFP that a variety of features indicative of a former ocean were found around the Zhurong landing area, including “pitted cones, polygonal troughs and etched flows”.
Previous studies have suggested that crater-like cones may have formed from mud volcanic eruptions and often formed in areas where water or ice once existed.
Searching for the Martian ocean shoreline
Information from the rover, as well as satellite data and analysis done on Earth, also indicated that a shoreline once existed there, according to the study. The team of researchers calculated that the ocean was formed by flooding nearly 3.7 billion years ago. Afterward, the ocean froze over, etching the shoreline before disappearing just over 3.4 billion years ago, according to their scenario.
Bo pointed out that the team “does not claim that our findings definitively prove the existence of an ocean on Mars.” This level of confidence will probably require a mission to return some Martian rocks to Earth for more detailed study.
Skepticism of scientists
Benjamin Cardenas, a scientist who analyzed other evidence for the existence of a Martian ocean, told AFP he was “skeptical” of the new study.
He believes that researchers have not given enough consideration to how much Martian wind has scattered sediments and eroded rocks over the past few billion years. Cardenas pointed to past studies showing that, even “the slow rate of Martian erosion, would have destroyed evidence of the shoreline over such a long period of time.”
In turn, Bo admitted that wind could have eroded some rocks, but said the impact of meteorites falling on Mars could also “occasionally excavate underground rocks and sediments to the surface.” While the overall theory remains controversial, Cardenas said he tended to think Mars had an ocean.
Provided by phys.org
