In the 1970s, images from the NASA Mariner 9 orbiter revealed water-sculpted surfaces on Mars. This settled the once-controversial question of whether water ever rippled over the red planet. Since then,

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.

Ground-penetrating radar data obtained by China's Zhurong rover has revealed buried beneath the Martian surface evidence of what look like sandy beaches from the shoreline of a large ocean that may have existed long ago on the northern plains of Mars.

Mars – dusty, dry, and desert-clad – was once so rich in water it had not just lakes, but oceans, according to a new study. Observations using ground-penetrating radar have revealed underground features consistent with beaches on the red planet,