At last, the missing storm clouds on Saturn’s moon Titan may have been found.
In the last decade, researchers have monitored clouds at both of Titan’s poles, where large lakes of methane have been spotted by Earth-based observers and by the Cassini spacecraft, which has been orbiting the moon for the last three years. But the moon’s clouds seemed inexplicably confined to those areas.
“We’ve seen a lot of clouds at the poles. But we’d never seen a major storm at the equator,” said Michael Brown, a professor of planetary astronomy at Caltech.
This result has had scientists scratching their heads. When the European probe Huygens parachuted to the surface of Saturn’s large moon from NASA’s Cassini spacecraft in January 2005, the probe’s cameras showed what looked to geologists to be dry channels left by methane rivers cutting through dune fields in the equatorial zone.
If there were no storms at the equator, scientists wondered, what made the river channels? “Some people even suggested maybe these are not rain-carved,” Brown said.
Now, Brown and one of his former graduate students, Emily Schaller, have found the first evidence of a storm over Titan’s tropical latitudes. Their research, titled “Storms in the tropics of Titan,” is published in this week’s journal Nature.