Saturn Moon's 'Lake Ontario': Shallow and Virtually Wave-free

This image of Ontario Lacus, the largest lake in the southern hemisphere of Saturn's moon Titan, was obtained by NASA's Cassini spacecraft on Jan. 12, 2010

SAN FRANCISCO — A giant hydrocarbon lake on Saturn's moon Titan is mirror-flat and surprisingly shallow, with average depths comparable to that of a backyard swimming pool, according to a new study. Ontario Lacus, the largest lake in Titan's southern hemisphere, covers about 6,000 square miles (15,000 square kilometers). While big, it's not exactly fierce; Ontario's waves are less than a dime's-width high, and the lake can't be any deeper than 24 feet (7.4 meters) in any one spot, researchers found. 

Ontario Lacus is the biggest of these lakes south of Titan's equator. It spans a huge area — nearly as much as its Earth namesake, North America's Lake Ontario. The team also looked at a few lakes in Titan's northern hemisphere, which has considerably more lakes than the south. One of them, the huge Ligeia Mare, was deeper — though the researchers couldn't put a hard number on how deep it goes, since Cassini's radar signal lessens in strength beyond depths of 26 feet (8 meters) or so.