Mystery of Titan's disappearing 'island'

Astronomers have been left baffled by the rise and subsequent fall of a huge feature in a sea on Saturn's moon Titan. In July 2012 a giant feature 100 square miles (260 square kilometers) in area - roughly the area of 58,000 football fields - is seen surfacing from under the liquid before partially disappearing again. No definitive explanation is yet apparent. Several theories currently exist including surface waves, rising bubbles, floating solids, solids suspended just below the surface or 'something more exotic' according to NASA.

The mysterious feature appears bright in the radar images, suggesting it has a somewhat similar composition to the land nearby in the image. This supports one theory that it may be a solid structure - potentially an island - that surfaced from under the liquid before sinking again for an unknown reason.

http://www.dailymail.co.uk/sciencetech/article-2774811/Mystery-moving-island-Titan-Giant-object-58-THOUSAND-football-fields-size-rises-sinks-Saturn-s-moon.html