Titan, the largest of Saturn’s more than 60 moons, has surprisingly intense rainstorms, according to research by a team of UCLA planetary scientists and geologists. Although the storms are relatively rare — they occur less than once per Titan year, which is 29 and a half Earth years — they occur much more frequently than the scientists expected.
The storms create massive floods in terrain that are otherwise deserts. Titan’s surface is strikingly similar to Earth’s, with flowing rivers that spill into great lakes and seas, and the moon has storm clouds that bring seasonal, monsoon-like downpours, Mitchell said.
“I would have thought these would be once-a-millennium events, if even that,” said Jonathan Mitchell, UCLA associate professor of planetary science and a senior author of the research, which was published Oct. 9 in the journal Nature Geoscience.
Sean Faulk, a UCLA graduate student and the study’s lead author said the study also found that the extreme methane rainstorms may imprint the moon’s icy surface in much the same way that extreme rainstorms shape Earth’s rocky surface.
On Earth, intense storms can trigger large flows of sediment that spread into low lands and form cone-shaped features called alluvial fans. The Cassini mission ended in September 2017, when NASA programmed it to plunge into the planet’s atmosphere as a way to safely destroy the spacecraft.
The scientists primarily used computer simulations to study Titan’s hydrologic cycle because observations of actual precipitation on Titan are difficult to obtain and because, given the length of each year on Titan, Cassini only observed the moon for three seasons. temperature contrasts on Earth produce intense cyclones in the mid-latitudes, which is what creates the storms and blizzards that are common during the winter months across much of North America.
The research was funded by a NASA Cassini Data Analysis and Participating Scientists Program grant.