Mars may have been a "blue planet" with an ocean the size of today's Arctic Ocean, a new study suggests.

Mars today is a frozen, dusty desert. But if you look deep inside Valles Marineris, the largest canyon system on Mars and in ...

Ancient shoreline features hint that water on Mars once formed a vast ocean.

The existence of water on Mars has been a hot topic in planetary science, with several studies having already provided evidence of water bodies on the Red Planet, which indicate that it might have had ...

As you travel from the middle of Mars toward its northern regions, the landscape changes dramatically. In an area called Coloe Fossae, long shallow grooves stretch across deep valleys, scattered ...

Spacecraft orbiting the Red Planet have helped researchers map out an ancient coastline that surrounded a large ocean billions of years ago ...