Aug 16, 2011 08:42 GMT  ·  By

Experts investigating Titan, the largest moon orbiting Saturn, recently discovered a white arrow on the object's surface. About the size of Texas, this structure went unexplained for quite some time. Now, scientists at the University of California in Los Angeles propose an explanation for its existence.

The UCLA team says that these sharp, surprising cloud shapes are produced via a stenciling effect. The effect itself is produced by atmospheric waves that act at a planetary scale, influencing the odd moon's climate patterns to a great extent.

Astronomers have known for years that Titan's atmosphere is very odd, although very similar to Earth's in many respects. The new investigation was conducted using data collected by the NASA Cassini spacecraft, which has been orbiting Saturn since July 1, 2004.

In the past seven years, Cassini has snapped countless images of the gas giant, its ring system and its moons, allowing astronomers to better understand how this system functions. However, the more in-depth studies were conducted of Titan, the more its atmosphere revealed amazing features.

“These atmospheric waves are somewhat like the natural, resonant vibration of a wine glass. Individual clouds might 'ring the bell,' so to speak, and once the ringing starts, the clouds have to respond to that vibration,” says Jonathan L. Mitchell.

The UCLA team leader holds an appointment as an assistant professor of Earth and space sciences, and of atmospheric and oceanic sciences. He explains that these sharp clouds, including the white arrow-shaped one, can produce intense precipitations.

At times, these precipitation levels can exceed more than 20 times Titan's average seasonal rainfall. If this discovery is verified, then experts may have just found one of the main mechanisms that account for why the moon's surface is so eroded.

Details of the new investigation appear in the August 14 online issue of the esteemed journal Nature Geoscience, and are also scheduled to appear in an upcoming print issue of the top science magazine.

According to the UCLA team, the entire moon is subjected to a tropical climate, which means that it experiences the same conditions and weather phenomena that are confined to Earth's equatorial areas.

“Our new results demonstrate the power of this analogy, not only for general features of Titan's climate but also for individual storms. In future work, we plan to extend our analysis to other Titan observations and make predictions of what clouds might be observed during the upcoming season,” Mitchell explains.

“Titan's all-tropics climate gives us the opportunity to study tropical weather in a simpler setting than on Earth. Our hope is that this may help us understand Earth's weather in a changing climate,” the expert concludes.