Saturn Moon Titan May Offer Look into Earth's Future

Recent discoveries on Saturn's moon, Titan, is revealing that it may not be so different from our world in the impending centuries to come. The moon is characterized by giant dunes and an oceanless surface, which may foreshadow Earth's desert future. Studies show that the moon is the closet analog to Earth that has ever been found.

According to Live Science, Jonathan Lunine, a Cassini-Huygens scientist at the University of Arizona, said that "Titan may be very different from Earth today, but maybe not Earth tomorrow."

Until recently, the surface of Titan was majorly unknown to scientists until the Huygens probe penetrated the hazy atmosphere in 2005. After seven years, the Cassini spacecraft carrying Huygens finally reached Titan, and detached from the spacecraft, parachuting down to Titan's surface, all the while transmitting four hours worth of valuable data. The mission was not only conducted by NASA, but also the European Space Agency and the Italian Space Agency.

Francois Raulin, who is also a Cassini-Huygens scientist like Lunine, at the Laboratory of Environmental Physics and Chemistry in Paris states that this expedition was a goldmine of information, saying that "Even though we have only four hours of data, it is so rich that after two years of work we have yet to retrieve all the information it contains." This delay may stem from the calibrations and cross-checking of Huygens instruments to get credible results.

Periodic rain

Images shot from Huygens now show that Titan has extremely rugged terrain in the bright highlands north of the probe's landing site. This is characterized by enormous ridges of 500 to 650 feet high that flank channels at a 30 degree angle. Scientists draw conclude from this image that these may be drainage channels, very much like Earth's valleys, that are cut by liquid methane falling as rain as detailed by the Planetary and Space Science magazine.

"Though there is rain on Titan, they are spaced by hundreds to thousands of years between periods of torrential rains, unlike Earth that is spaced by months to years. The reason being that because Titan is much farther from the sun than Earth is, it takes much more time for the sun to evaporate the methane and build it up in the atmosphere enough to generate storms," Lunine said.

On Titan, it appears that methane moves from the atmosphere to the surface and back again in this cycle that is very much seen with Earth's water cycle. To Lunine, "All the processes seen on Titan are in some sense connected with Methane, just as processes on Earth are in some sense involved with water."

Desert world

In the past, scientists believed that Titan's surface would be covered with oceans of liquid methane and ethane, which would explain the hazy atmosphere. But now, after Huygens successful voyage down to Titan's surface, scientists found giant dunes most likely made of sugar-sized hydrocarbon grains that stretch up to 60 miles long across dark plains at the equator. Scientists believe that any lakes and seas that were previously motioned might lie at Titan's Polar Regions.

To Lunine, "There's a sense of a desert world on Titan. Not like Earth's desert but rather the characterization of a very dry place. Titan lacks oceans, but someday Earth will too as the sun increases in brightness, and eventually boils away the oceans leaving Earth a desert planet."

Hidden liquid

The search for Titan's liquid elements is still continuing. But radio waves detected by Huygens could shed light as to where the liquid is hiding, perhaps deep below the surface, and released by geysers of vulcanism.

Huygens sensor, the Permittivity, Waves and Altimetry (PWA) sensor detected an extremely low frequency (ELF) radio wave during its descent. If this signal is naturally emitted, then the ELF waves might reveal any oceans that may exist below Titan's surface and how deep they are. Currently, researchers have already ruled out the possibility of the frequency being electrical interference from the instrument itself. As of right now, nobody is sure what generated this ELF wave in the first place.

Fernando Simões of the PWA team suggest that it might be "An interaction with Saturn's magnetosphere or related to Titan's natural fields. Either way, Titan is proving to be a fascinating environment."

Charles Q Choi. "Earth's Future Glimpsed on Titan." Live Science. http://www.livescience.com/space/scienceastronomy/070612_st_huygens_titan.html