Ice Cloud Marks Fall on Titan Moon of Saturn

If the latest data coming in from space is correct, it looks like NASA scientists are now able to tell that the largest moon of Saturn, known as Titan, is in for a long fall-seven years long.

Space.com reports that the latest images and data transmitted from NASA's Cassini spacecraft shows that an icy cloud has begun expanding over the south pole of the Titan moon. This points to a long fall season starting on the moon.

New cloud patterns are starting to take shape at Titan's south pole as a result of the changing seasons, as demonstrated by several images from Cassini that showed a vortex hovering over the south pole.

"We associate this particular kind of ice cloud with winter weather on Titan, and this is the first time we have detected it anywhere but the north pole," the study's lead author, Donald E. Jennings of NASA's Goddard Space Flight Center in Greenbelt, Md, said in a statement.

At the north pole of Titan, it is currently spring time, Space.com notes.

The presence of the ice cloud shows a change in direction of a key pattern of global air circulation on Titan. When scientists first picked up on the pattern of air circulation from Titan, the warm air from the southern hemisphere was climbing in the atmosphere before getting sent to the colder north pole, where it sank down to lower layers in the atmosphere and formed ice clouds.

The north pole of Titan began changing from winter to spring in August 2009, when scientists believe that the change in the air circulation started. But scientists didn't see the southern ice cloud until last July, and there were only slight hints that there was a shifting in the patterns around the south pole in early 2012-when the Cassinni satellite picked up a swirling polar vortex and other signs indicating cold weather in the region.

"This lag makes sense, because first the new circulation pattern has to bring loads and loads of gases to the south pole. Then the air has to sink. The ices have to condense. And the pole has to be under enough shadow to protect the vapors that condense to form those ices," Carrie Anderson, a CIRS team member and Cassini participating scientist at NASA Goddard said in a NASA statement.

In terms of what makes up the clouds, so far, scientists have said that chemicals have not played a role in forming the ice clouds. There is a theory that the clouds could be made up of a mixture of organic compounds. However, whatever does make up those clouds may hold the answer to what makes up the atmosphere of Saturn's largest moon.

"What's happening at Titan's poles has some analogy to Earth and to our ozone holes," said the CIRS Principal Investigator, NASA Goddard's F. Michael Flasar. "And on Earth, the ices in the high polar clouds aren't just window dressing: They play a role in releasing the chlorine that destroys ozone. How this affects Titan chemistry is still unknown. So it's important to learn as much as we can about this phenomenon, wherever we find it."