What if Mars was just like Earth—or at least an approximation? Because what the European Space agency has discovered sure suggests the martian planet has seen better days. Maybe it wasn't always the barren, lonely desert we've always made it out to be.

The agency has released some very striking 3D images of Mars' Reull Vallis region, which shows a 932-mile-long "river" that runs from the planet's Premethei Terra Highlands to the vast Hellas basin. Like a real life Pandora, but more red. At its widest, researchers estimate the riverbed spanned 4.3-miles, with a depth of up to 984 feet. And similar to rivers here on Earth, Mars' supposed liquid intestine was fed by "numerous tributaries."

Scientists estimate that water may have flown through the now dry torrent about 3.5 to 1.8 billion years ago. Supposedly the region was invaded by a glacier, which eventually carved the large valley you see above. Very Earth-like—the Grand Canyon is such an example of water performing its handy work.

NASA's Curiosity Rover is currently investigating the planet for evidence of water, and is actually going to perform some tests soon. What mysteries are lying beneath its surface, I wonder? Above ground, despite its desert-like appearance, it sure resembles some of Earth's geography. Maybe that's why some are so anxious to explore the Red Planet.