Scientists have used orbiters and rovers to find dried streams, lakes, and gullies on Mars that hint at its watery past, but their cavalry of robots has struggled to prove the Red Planet ever had an actual ocean.

Data from China's Zhurong rover on Mars suggests an ancient ocean and strengthens evidence that the planet was once warm, wet, and habitable.

A Chinese rover found evidence of ancient beaches on Mars, suggesting the planet once had vast oceans 4 billion years ago. The discovery of sloping sand layers beneath the surface provides new insights into Mars' watery past.