Craters on Saturn’s largest moon could have resulted from nitrogen blasting from below ground.

Some of the small lakes on Saturn’s moon Titan were born of big bangs, scientists suggest.

Liquid methane and ethane collect in low-lying basins on Titan, creating lakes and seas — features that are rare in the Solar System. Scientists had thought that the basins formed when liquid methane dissolved some of the minerals in Titan’s crust, causing it to collapse. A similar process causes sinkholes to appear in limestone on Earth.

A team led by Giuseppe Mitri at d’Annunzio University in Pescara, Italy, took a closer look at some of Titan’s small lakes using data gathered by NASA’s Cassini spacecraft. The scientists noticed that many of these lakes have tall rims that rise steeply from the surrounding terrain. On Earth, similar rims are seen on craters that form when water and magma interact underground and then explode through the surface.

Titan’s small lake basins might have taken shape when temperatures rose, causing buried nitrogen to vaporize and suddenly blow out through the moon’s crust.