Ready to huck the lunar gnar? The European Space Agency (ESA) has unveiled the first-ever picture of an active river system on another world. The photo was taken by the Cassini probe over Saturn’s largest moon, Titan, and shows a river system over 400km long stretching from its headwaters to a large sea. Radar imaging shows a smooth, consistent surface in the river valley, which scientists say indicates the presence of liquid, most likely methane or ethane. Liquid ethane was confirmed on the moon's surface in 2008 and Titan remains the only other known world with stable liquid on its surface.
"This radar-imaged river by Cassini provides another fantastic snapshot of a world in motion," said ESA Cassini Project scientist Nicolas Altobelli. The Cassini mission is a cooperative project of NASA, ESA, and ASI, the Italian space agency.