Titan continues to demonstrate that icy worlds can be as active as our warm, cozy planet. Saturn’s moon has not only got a hydrocarbon ocean and a rich atmosphere, the latest observations show canyons hundreds of meters deep.
An international group of astronomers, led by Valerio Poggiali of the University of Rome, looked at radar data collected by the Cassini spacecraft in May 2013. The radar is used to peer through the moon's thick atmosphere, and in this case, record the altitude of the feature.
The canyons have a depth between 240 to 570 meters (790 to1,870 feet) and are quite narrow, less than a kilometer (less than half a mile) across. They are very steep, with slopes at over 40 degrees. At the bottom of the canyons, researchers found the distinct signature of liquid hydrocarbons, which is the component of the large oceans that cover Titan.
The findings, published in Geophysical Research Letter, show that some of the liquid is at sea level around Ligeia Mare, while the rest flows from tributaries above sea level. The researchers are unsure how these canyons came to be. Fast or slow erosion, sudden terrain uplift, and changes in sea levels are all being considered.
"It's likely that a combination of these forces contributed to the formation of the deep canyons, but at present it's not clear to what degree each was involved. What is clear is that any description of Titan's geological evolution needs to be able to explain how the canyons got there," said Poggiali in a statement.
On our planet, there are just as many ways for canyons to form. The most famous is probably the Grand Canyon carved by the Colorado River, which is an example of terrain uplifting. Intermitting flowing and slow carving can be seen in the Fish River Canyon in Namibia as well, and there are thousands of other examples around the world.
"Earth is warm and rocky, with rivers of water, while Titan is cold and icy, with rivers of methane. And yet it's remarkable that we find such similar features on both worlds," said co-author Alex Hayes, a Cassini radar team associate at Cornell University, Ithaca, New York.
The team will use further observations to study more regions of Titan, and hopefully crack the mystery of this fascinating moon.