(AP) Talk about cold, miserable weather! When dawn comes on Titan it's nearly 300 degrees below zero with a steady drizzle. And the drizzle is methane _ an explosive gas on Earth that is chilled into a liquid on that moon of Saturn, astronomers report in Thursday's online edition of the journal Science.
Other than that, they say, weather there may follow processes similar to weather here.
Researchers led by Mate Adamkovics of the University of California, Berkeley, studied Titan, Saturn's largest moon, using near-infrared images from Hawaii's W. M. Keck Observatory and Chile's Very Large Telescope.
In most of the images, methane clouds and drizzle are seen in the morning.
"Titan's topography could be causing this drizzle," said Imke de Pater, also an astronomer at U.C. Berkeley. "The rain could be caused by processes similar to those on Earth: Moisture laden clouds pushed upslope by winds condense to form a coastal rain."
Depending on conditions, the drizzle could hit the ground or turn into a ground mist, the researchers said.
They reported that the drizzle seems to dissipate after what would be about 10:30 a.m. Titan time, if the day there were divided into 24 hours. However, because Titan takes 16 Earth days to rotate once, the drizzle continues for about three Earth days after sunrise.
The research was supported by the National Science Foundation, the Technology Center for Adaptive Optics at the University of California at Santa Cruz, NASA and the Center for Integrative Planetary Science at U.S. Berkeley.