New evidence of ancient rivers suggests Mars may have been a "blue planet," thanks to an ocean spanning its entire northern ...

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

Mars, now a dusty world of rusted rock and thin air, once carried enough water to transform its face into something far more ...

Using images from cameras on Mars orbiters, an international research team has discovered structures on Mars that are very ...

Three billion years ago, you could have stood on Mars and watched a river spill into a sea. That picture is still speculative ...

Scientists have traced ancient Martian shorelines inside a giant canyon, revealing where a vast ocean once stood and why ...

Mars is absolutely dripping with evidence that the red planet was once a striking blue, complete with glistening lakes, ...

Scientists have discovered evidence of a massive ancient ocean on Mars, providing new insights into the planet's history when it was abundant with water.

Billions of years ago, it rained on Mars. The water collected in valleys and rivers, filled and spilled over the rims of craters, and was funneled into canyons, perhaps even making its way to a large ...

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

Long before Mars turned into the frozen desert you see today, water shaped its surface in dramatic ways. Rivers cut through highlands, lakes pooled inside craters, and floods tore open canyon walls.