Researchers have found new evidence for a massive subsurface ocean on Mars, again raising the possibility of microbial life.

Billions of years ago, Mars may have looked very different. The Mars ocean theory has been a subject of scientific debate and ...

The “Mars ocean theory” has long been the topic of discussion among scientists and cartographers due to Mars’s geography, which suggests a large northern ocean once existed on its surface.

Many scientists think that Mars used to have an ocean that covered up to a third of the planet, but the theory is still debated. New data from China's Zhurong rover strengthens the case for an ...

Other conundrums, such as what happened to the water, also cast doubt on this theory. The polar ice caps do not contain enough water to fill such an ocean. Subsequent missions to Mars, however ...

These findings also help support the theory that Mars once had a massive ocean. "The structures don't look like sand dunes. They don't look like an impact crater. They don't look like lava flows. That ...

Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. Mars may have once ...

A team of geologists at the Chinese Academy of Geological Sciences, the Institute of Space Sciences and the Shandong ...