Scientists see storm brewing over Titan's tropical desert

Washington, August 13 (ANI): A new research has discovered significant cloud formation within the tropical zone near the equator of Saturn's largest moon, Titan, which is evidence that the parched, dry desert of the natural satellite can support large-scale storms.

The evidence comes from a team of US astronomers using the Gemini North telescope and NASA's Infrared Telescope Facility (IRTF) both on Hawaii's Mauna Kea.

Titan, the solar system's second largest moon, has received considerable attention by scientists since NASA's Cassini mission deployed the Huygens probe that descended through the moon's atmosphere in January 2005.

During its descent, the probe's cameras revealed small-scale channels and what appear to be stream beds in the equatorial regions that seemed to contradict atmospheric models predicting extremely dry desert-like conditions near the equator.

Until now, these erosional (fluvial) features have been explained by the possibility of liquid methane seeping out of the ground.

"In April 2008, we observed what was a global event that shows how storm activity in one region can trigger clouds, and probably rainfall, over arid regions, such as the tropics where Huygens landed," said team member Henry Roe from Lowell Observatory.

Prior to this event (in April 2008), it was not known whether significant cloud formation was possible in Titan's tropical regions.

This activity in Titan's tropics and mid-latitudes also seems to have triggered subsequent cloud development at the moon's south pole where it was considered improbable due to the Sun's seasonal angle relative to Titan.

"Of course these rain showers are not liquid water like here on Earth, but are instead made of liquid methane. Just like the streambeds and channels that are carved by liquid water on Earth, we see features on Titan that have been created by flowing liquid methane," Roe added.

The team monitored Titan on 138 nights over 2.2 years and during that time cloud cover was well under one percent.

Then, mid-April of 2008, just after team member Emily Schaller had handed in her doctoral dissertation focusing on Titan's minimal cloud cover she noticed the dramatic increase in cloud cover.

During this three-week episode, clouds forming at about 30 degrees south latitude were observed, followed several days later by clouds closer to the equator and at the moon's south pole.

The apparent connection between the cloud formations leads to the possibility that cloud formation in one area of the moon can instigate clouds in other areas by a process known as atmospheric teleconnections. (ANI)