Chinese Mars rover Zhurong has discovered new evidence supporting the hypothesis that Mars was once covered by a massive ocean. These findings include traces of an ancient coastline where water may have once splashed. The idea of a vast ocean covering a third of Mars billions of years ago has long been a topic of debate among scientists.
The Zhurong rover, which touched down in 2021 in Mars’ Northern Hemisphere in the Utopia area where signs of ancient water had previously been found, has been exploring the Martian surface. Data from this mission has recently been published in the journal Nature. Within the landing site, various features have been identified that suggest the presence of a past ocean, such as conical formations, polygonal recesses, and eroded flows, some of which resemble mud volcano traces typically found in areas with past water or ice presence.
Based on data collected by the Zhurong rover and satellite images, scientists propose that the ocean may have formed around 3.7 billion years ago due to flooding events, with a coastline forming later and disappearing approximately 3.4 billion years ago. However, the study’s lead author acknowledges that further evidence, such as studying samples of Martian rocks brought back to Earth, is necessary to confirm the ocean’s existence.
Some scientists remain skeptical of these findings, pointing out that Martian winds over billions of years could have erased traces of the ancient coastline. Research indicates that even low erosion rates on Mars could eventually eliminate any signs of a coastline.
Nevertheless, the concept of a past ocean on Mars is significant as it could have made the planet more habitable. On Earth, life is believed to have originated in underwater locations with hot gases and minerals, or in coastal zones where water meets land. The potential presence of an ancient ocean on Mars further piques interest in studying the planet for clues about extraterrestrial life.