Cassini Watches Clouds Form Over Titan’s Methane Sea
What’s the weather forecast on Titan? Well if you’re planning a vacation down by the shores of Ligeia Mare you may get some cloudy skies, if what happened at the end of July repeats itself!
The animation above was made from images acquired by Cassini during a flyby of Titan in July 2014, showing the formation and dissipation of bright methane clouds over one of the moon’s polar lakes. Spanning a period of two days, the images reveal what may be the start of summer weather in Titan’s northern hemisphere… or just a bit of isolated “lake effect” cloudiness.
The spacecraft captured the views between July 20 and July 22, 2014, as it departed Titan following a flyby. Cassini tracked the system of clouds as it developed and dissipated over Ligeia Mare during this two-day period. Measurements of the cloud motions indicate wind speeds of around 7 to 10 miles per hour (3 to 4.5 meters per second).
The timing between exposures in the sequence varies. In particular, there is a 17.5-hour jump between the second and third frames. Most other frames are separated by one to two hours.
Further monitoring should help determine if the clouds’ appearance signals the beginning of summer weather patterns on Titan or if this is an isolated occurrence.
“The lack of northern cloud activity up til now has surprised those studying Titan’s atmospheric circulation. Today’s reports of clouds, seen a few weeks ago, and other recent indicators of seasonal change, are exciting for what they imply about Titan’s meteorology and the cycling of organic compounds between northern and southern hemispheres on this unusual moon, the only one in our solar system covered in liquid organics.”
– Carolyn Porco, Cassini Imaging Team Leader and CICLOPS Director
Ligeia Mare is the second-largest body of liquid methane on Titan’s surface, one of many clustered around its north pole. It recently was a subject of interest when the reappearance of a “magic island” was observed by Cassini.