Ocean on Titan, and salt on Mars

Scientists believe that an ocean of water and ammonia may exist below the surface of Saturn's largest moon, Titan. The findings appear in the March 21 issue of the journal Science.

The evidence of an underground ocean on Titan comes from observations by the Cassini spacecraft, which has visited Titan 19 times over the past three years.

Scientists marked 50 identifiable locations on Titan from Cassini radar data, and observed that, over time, many had moved up to 19 miles from where they were predicted to be. This led to the conclusion that the planet's crust may separated from the core by an ocean.

This graphic shows a cross-section of Titan showing an ocean that could be 62 miles below the moon's crust.