NASA's spacecraft known as Cassini has revealed significant seasonal changes in atmospheric temperature and composition of Saturn's largest moon, Titan, according to the space agency's official website.
It is believed that during this period winter takes control of Titan's southern hemisphere and powerful vortices circling in the atmosphere form currents in the upper atmosphere over the South Pole. The Cassini probe was able to detect that one of these vortices was enriched in trace gases, a very rare occurrence in Titan's atmosphere.
“For a long time, the Cassini mission and the constant flyby of Titan allowed us to observe the picture of seasonal changes on Titan in great detail,” said Athena Kostenis, a member of the Cassini infrared spectrometer team at the Paris Observatory. “We arrived at the checkpoint in midwinter and were able to monitor Titan's atmospheric changes over two full seasons.”
Kostenis will present the group's findings at a joint meeting of the 48th division of the American Astronomical Society for Planetary Sciences and the 11th European Planetary Science Congress (EPSC) this week in Pasadena, California, USA.
Just months after the vortex emerged in the stratosphere over the South Pole, it became visible as a 'hot spot' at high altitudes. At the same time, the corresponding features in the northern hemisphere had almost disappeared by 2011. Inside the polar vortex above the increasingly shaded South Pole, there is a rapid build-up of trace gases that accumulate in the absence of ultraviolet sunlight. These include complex hydrocarbons that were previously only seen at high northern latitudes.
Sources: NASA
