Methane Rain on the Saturnian Moon Titan

As spring continues to unfold at Saturn, April showers on the planet's largest moon, Titan, have brought methane rain to its equatorial deserts, as revealed in images captured by NASA's Cassini spacecraft. This is the first time scientists have obtained current evidence of rain soaking Titan's surface at low latitudes.

Extensive rain from large cloud systems, spotted by Cassini's cameras in late 2010, has apparently darkened the surface of the moon. The best explanation is these areas remained wet after methane rainstorms. The observations released today in the journal Science, combined with earlier results in Geophysical Research Letters last month, show the weather systems of Titan's thick atmosphere and the changes wrought on its surface are affected by the changing seasons, notes NASA JPL.

Near the beginning of the movie/animation made from images taken by NASA's Cassini spacecraft above, a particularly large cloud can be seen directly over and east of Titan's huge sea, Kraken Mare. If full, Kraken Mare, at 400,000 square kilometers (154,000 square miles), would be almost five times the size of North America's Lake Superior.

Over the past several years, Cassini has consistently observed clouds at Titan's mid-southern latitudes. More recent images also show clouds close to the moon's equator (see PIA12810). These observations provide evidence of a seasonal shift of Titan's weather systems to low latitudes following the Saturnian system's August 2009 equinox. (During equinox, the sun lies directly over the equator.)