Titan's lost seas found

摘要

When the Cassini spacecraft found no methane ocean swathing Saturn's moon Titan, it was a blow to proponents of an Earth-like world. The discovery of northern lakes on Titan gives them reason for cheer. The saturnian moon Titan is the second largest satellite in the Solar System, trumped only by Jupiter's Ganymede. It is the only Solar System satellite with a dense atmosphere, which produces a surface pressure 1.5 times that at Earths surface. And it shares with Earth the peculiarity that nitrogen is the principal component of its atmosphere. The list of similarities does not end there, and, as Stofan et al. report, it has just been augmented. The authors' account of what seem to be lakes at high northern latitudes on Titan appears on page 61 of this issue.