NASA has spotted a giant polar vortex brewing on Titan as winter sets in on the satellite's South Pole, Nature World Report reports.
The new cloud was found in the lower stratosphere, where temperatures are even colder.
The ice particles of the giant cloud are formed of a variety of compounds containing hydrogen, carbon and nitrogen. The sinking gases face colder and colder temperatures on the way down. Different gases condense at different temperatures, resulting in a layering of clouds over a range of altitudes.
Carrie Anderson, the lead researcher for this, said that the new cloud spans about 5 degrees in latitude, according to DailyMail.com.
This means the cloud is about 150 miles (240km) across. Scientists expect it to have a low density, which is similar to Earth's fog.
Using the Composite Infrared Spectrometer, or CIRS, Cassini's infrared instrument detected the new cloud. Cassini has been catching glimpses of the change from fall to winter at Titan's South Pole since the past few years. Cassini had arrived at Saturn during mid-winter at Titan's north pole in 2004.
It is the first time that any spacecraft has seen the onset of a Titan winter.
With the help of the images captured by Cassini's camera, scientists have been able to decipher the nature and severity of Titan's winter as they analyze the size, altitude and composition of the polar ice clouds present there. They have concluded that the temperatures at the south pole must get down to at least -238 degrees Fahrenheit (-150 degrees Celsius).
Scott Edgington, Cassini deputy project scientist at NASA's Jet Propulsion Laboratory said that witnessing Titan's seasonal changes is exciting and surprising.
'The opportunity to see the early stages of winter on Titan is very exciting,' said Robert Samuelson, a Goddard researcher working with Anderson added.
