UNITED NEWS INTERNATIONAL (UNI) — Astronomers found an oddly-shaped crater on Mars that might have once held water.

NASA recently released an image taken by its Mars Reconnaissance Orbiter showing an impact crater that looks like a disk with a tail, or, in NASA’s words, a tadpole.

The U.S. space agency said the shape is the result of water that flowed outwards from the crater, forming a long, whip-like valley.

They were able to tell the water flowed outward instead of inward because the crater is at a higher elevation than the valley, meaning water would have flowed out and down.

But that flowing water that scientists say once existed hasn’t been around for a long, long time. 

Scientists think the Martian landscape was once marked by deep, blue oceans beneath skies of fluffy white clouds.

But those oceans somehow ran dry and disappeared, along with any life it sustained.