Moon of Saturn May Get Rain

In a forecast of methane rain, astronomers have captured the first images of clouds on Titan, which confirms suggestions that the distant moon of Saturn has summer storms like those on Earth.

The vast, glowing clouds, most likely formed of methane rather than water vapor, drift high in Titan’s cold, smoggy atmosphere near the moon’s south pole. They were discovered by Caltech planetary astronomer Michael Brown and his colleagues at UC Berkeley using the W.M. Keck II 10-meter and Gemini North 8-meter telescopes atop Mauna Kea in Hawaii.

“I am looking out my office window now and seeing clouds. They are white,” Brown said. “The clouds on Titan look the same.”

The clouds came as something of a surprise because previous images of Titan had revealed only unchanging surface markings and very gradual seasonal changes in the haze, making the moon look “like L.A. on a bad day,” Brown said.

But since December 2001, the clouds have been visible almost every night, invariably as a single large plume almost always in the same general area of the south pole.