In July of this year, images taken by NASA’s Cassini spacecraft show a mysterious feature in a vast hydrocarbon sea on the Saturn’s moon Titan. Astronomer have explained this features with a wide range of ideas like rising bubbles, floating solids or surface waves but these ideas are just random guesses. Stephen Wall from the Jet Propulsion Laboratory in a news release says “"Science loves a mystery, and with this enigmatic feature, we have a thrilling example of on-going change on Titan. We're hopeful that we'll be able to continue watching the changes unfold and gain insights about what's going on in that alien sea." This mysterious feature covers about 160 square kilometres of area of titan’s surface and it’s also been detected at least twice by Cassini during Titan flybys in 2013 and Cassini spacecraft has captured it once again in august of 2014. According to previous observation of titan’s surface, no sign of bright features has been found. Three images shown below were taken from Cassini Synthetic Aperture Radar data and these images show the presence and growth of the feature, which looks bright here beside the dark background of Ligeia Mare (Titan’s biggest sea).
Image Credit: NASA/JPL-Caltech/ASI/Cornell
Most of the white regions symbolize land surface that's above or like, just below the surface of the sea, which is supposed to be mostly composed of methane and ethane. Right after this mysterious feature was first dotted early last July, the feature seemed to disappear over the next numerous months. But just in last month, it was noticeable again and its look had transformed. Not only was the shape altered, but it also appeared to have doubled from 75 square kilometres. The scientists think that its appearance could be connected to the varying of seasons on Titan. Scientists are confident that the feature isn’t an outcome of an artifact or fault in their data, or even just evaporation in the sea. Observing changes like these is a main objective for Cassini's present lengthy mission.