Polar Winds On Titan Make It Earth-Like

Researchers have found evidence for a polar wind on Titan, confirming earlier notions that Saturn's natural satellite is more Earth-like than other celestial objects in the solar system.

The Cassini Plasma Spectrometer (CAPS) instrument aboard the Cassini spacecraft detected electrons of a specific energy, during its numerous flybys of Titan. Cassini and its Titan lander Huygens found that the moon is losing about seven tonnes of its atmospheric hydrocarbons every year, which could not be explained until recently.

"Titan's atmosphere is made up mainly of nitrogen and methane, with 50% higher pressure at its surface than on Earth. Data from CAPS proved a few years ago that the top of Titan's atmosphere is losing about seven tonnes of hydrocarbons and nitriles every day, but didn't explain why this was happening. Our new study provides evidence for why this is happening," said Andrew Coates, the study's lead author.

Titan has a dense atmosphere like Earth. When sunlight hits the upper layers of the atmosphere, the ionosphere, it causes electrons to break away, leaving positively charged ions. These electrons ride the magnetic field around the moon and form an electric field. The field is strong enough to attract the ions into space, resulting in the winds seen mainly over the moon's poles.

The study has been published in the journal Geophysical Research Letters.