Artist's concept of astronauts exploring a dry gully on Saturn's moon Titan. - Ilustração de stock

Artist's concept of astronauts exploring a dry gully on Saturn's moon Titan. In early 2005 the European Space Agency's Huygens probe revealed a surface carved by numerous drainage channels similar to river deltas on Earth. While the exact nature of these channels is not yet known, one theory proposes that Titan's surface of hydrocarbon sediments has been washed from the highlands by methane rain.