Mars is cold and dry today, but the Red Planet was believed to be covered in oceans. Now, scientists examining data sent home by China's Zhurong rover think they've identified the shoreline, with sandy beaches lapped by waves. Zhurong's landing spot was chosen with this exact goal: going to a place on Mars that was thought to be the transition from an ocean to land. Its radar looked under the surface and found a structure that matched beach deposits on Earth.

Ancient beaches testify to long-ago ocean on Mars - Berkeley News

Chinese rover finds underground evidence of beach sediments likely deposited 4 billion years ago

Berkeley News (news.berkeley.edu)