Buttes and mesas in Mars' Chryse Planitia contain clay minerals made from liquid water interacting with the rock nearly 4 ...

Discoveries of clay minerals in Martian mounds by researchers indicate that Mars once had large bodies of water billions of ...

Researchers discover thousands of clay-rich hills on Mars, revealing evidence of ancient water and transforming our ...

The new work suggests that the edge of the dichotomy was eroded back by hundreds of kilometers during the time when an ocean ...

"It's possible that this might have come from an ancient northern ocean on Mars." Thousands of hills and mounds on Mars have been found to contain layers of clay minerals, which formed when ...

Research suggests that an ancient shoreline helped to sculpt the drop between Mars' southern and northern hemispheres.

The northern plains of Mars, marked by thousands of mounds and hills, hold significant evidence of the planet's watery past.

Related: Ocean's worth of water may be buried within Mars — but can we get to it? On Earth — for example, in the western United States — we find such hills in the form of buttes and mesas in ...

So the southern highlands appear to be older than the northern lowlands. Scientists also believe there was once a vast ocean ...