As different as each of the planets and moons are from Earth, NASA is finding many similarities as well. A recent study found that Venus may have at one time harbored life, and now the Cassini spacecraft at Saturn has found canyons on the surface of the moon Titan, some filled with liquid methane.
The narrow canyons, less than a kilometer wide in most cases, have very steep walls and vary in depth from 790 and 1870 feet. The fact that the canyons exist and are filled with liquid leads to the theory that liquid methane flows, or flowed, across the planet. Some of the canyons are above Titan’s “sea level,” leading to the question of how liquid methane was deposited at higher altitudes on the surface. Does it rain or snow methane? Was there some huge upheaval on the surface that lifted part of an ocean? Did sea level change? Researchers are not sure.
“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 Valerio Poggiali, Cassini team member.
On Earth, these processes were responsible for forming such surface features as the Grand Canyon and other places along the Colorado River in Arizona.
Image source: NASA and Mark Garlick