Cassini observed a giant ice cloud on Titan’s south pole as winter is setting in on Saturn’s moon. NASA released the images captured by the Cassini spacecraft just recently.
The giant ice cloud formed of frozen compounds is looming above Titan’s south pole, capturing part of the low and the mid stratosphere of the moon. In 2012, Cassini revealed another giant cloud looming over the same location, at 186 miles altitude. Now, the giant ice cloud is hovering at 124 miles altitude, much lower than the previously imaged cloud.
Cassini observed a giant ice cloud on Titan’s south pole. The Composite Infrared Spectrometer (CIRS), the infrared camera on NASA’s Cassini spacecraft, was used to image the giant ice cloud at thermal wavelengths that are invisible otherwise. Cassini is the first spacecraft to have the capacity to image the seasonal transition on Titan. One season on Titan last approximately seven and a half years as we measure them on Earth. When Cassini’s mission comes to an end in 2017, Titan’s south pole will still be transiting winter.
Carrie Anderson, scientist with NASA’s Goddard Space Flight Center (Maryland) stated that thanks to CIRS and the data collected the giant ice cloud became extraordinarily visible. It was unexpected, she stated. Nonetheless, it is a great opportunity to understand the processes shaping the seasonal transition on Saturn’s moon. The findings were presented on November 11th during the Meeting of the Division of Planetary Sciences of the American Astronomical Society.
Thanks to the data collected by Cassini, researchers are able to understand how ice clouds form on Titan’s south pole. The process bears some similarity to how rain clouds form above Earth. As water evaporates from the surface of the planet it meets cooler temperatures at it reaches the troposphere. When the altitude is high enough for condensation to occur, rain clouds are formed. The methane clouds hovering in the troposphere of Titan form in the same manner.
The polar clouds form above the troposphere due to circulation that takes gases from the warm pole of Saturn’s moon to the opposite pole. Warm air thus sinks, and the gases forming the air condense at the right cool temperatures found at different altitudes. Thus, several blankets of clouds form a giant ice cloud above the pole.
The data collected by Cassini also enabled scientists to determine the temperature that would enable the formation of the giant ice cloud over Titan’s south pole. At this point, it should reach -238 degrees Fahrenheit.
Photo Credits: imgur.com