MOSCOW, October 31 (RIA Novosti) — NASA’s Cassini mission captured some impressive photographs of sunlight glinting off hydrocarbon seas on Titan during a recent flyby of Saturn’s largest moon, the agency reported.
In the past Cassini had taken, separately, pictures of the polar seas on Titan’s surface and the sun light reflecting off them. But it is the first set of shots (stitched together like a mosaic) where the boundaries of the seas and the sunlight aura are visible in the same view.
According to NASA, "the sunglint, also called a specular reflection, is the bright area near the 11 o'clock position at upper left. This mirror-like reflection, known as the specular point, is in the south of Titan's largest sea, Kraken Mare, just north of an island archipelago separating two separate parts of the sea."
Surrounding Kraken Mare is a "bathtub ring" – an old coastline. Scientists suggest that earlier the sea was larger at some point, but evaporation has decreased its level.
The temperature on Titan’s surface is extremely low and water cannot exist in a liquid state. Instead, the seas are made up of liquid methane – a substance with a lower freezing point than water. Methane evaporates from Titan’s seas into the atmosphere, condenses as clouds and then precipitates back down onto the hydrocarbon surface. The process is similar to Earth’s water cycle and creates rivers, deltas and valleys on Titan’s surface.
Before Cassini’s arrival at Saturn, scientists believed that there might be bodies of open liquid on Titan’s surface. The spacecraft found not only fields of sand dunes near the equator and lower latitudes, but also located seas and lakes near the poles.
The new shots were captured by Cassini’s Visible and Infrared Mapping Spectrometer (VINS) on August 21.
The Cassini-Huygens orbiter is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. It was designed to study Saturn, its planetary rings and many natural satellites. Since arriving to the Saturn system in 2004, it has also observed Jupiter and tested the theory of relativity.