NASA's Cassini spacecraft has revealed giant lakes on Saturn's
moon Titan, one of which - at 39,000 square miles - is bigger than
Lake Superior.

One of Titan's lakes compared with Lake Superior

The features were captured by Cassini's radar near Titan's north
pole.
Although scientists can't be certain they're actually liquid-filled,
"their
dark appearance in radar that indicates smoothness and their other
properties point to the presence of liquids", as the NASA press
release explains.

If that's so, then the lakes' contents are likely to be a mixture of
ethans and methane "given the conditions on Titan and the abundance
of methane and ethane gases and clouds in Titan's atmosphere".

Dr Jonathan Lunine, Cassini interdisciplinary scientist at the
University of Arizona, said: "We've long hypothesized about oceans
on Titan and now with multiple instruments we have a first indication
of seas that dwarf the lakes seen previously."

Cassini scientists are now planning a May flypast aimed at
confirming the titanic Lake Superior is indeed filled with liquid.