Washington: A new research indicates that Saturn’s haze-enshrouded moon Titan turns out to have much in common with Earth in the way that weather and geology shape its terrain.
Wind, rain, volcanoes, tectonics and other Earth-like processes all sculpt features on Titan’s complex and varied surface in an environment more than 100 degrees Celsius colder on average than Antarctica.
“It is really surprising how closely Titan’s surface resembles Earth’s,” said Rosaly Lopes, a planetary geologist at the Jet Propulsion Laboratory (JPL) in Pasadena, California.
“In fact, Titan looks more like the Earth than any other body in the Solar System, despite the huge differences in temperature and other environmental conditions,” she added.
The joint NASA/ESA/ASI Cassini-Huygens mission has revealed details of Titan’s geologically young surface, showing few impact craters, and featuring mountain chains, dunes and even “lakes”.
The RADAR instrument on the Cassini orbiter has now allowed scientists to image a third of Titan’s surface using radar beams that pierce the giant moon’s thick, smoggy atmosphere.
There is still much terrain to cover, as the aptly named Titan is one of the biggest moons in the Solar System, larger than the planet Mercury and approaching Mars in size.
Titan has long fascinated astronomers as the only moon known to possess a thick atmosphere, and as the only celestial body other than Earth to have stable pools of liquid on its surface.
The many lakes that pepper the northern polar latitudes, with a scattering appearing in the south as well, are thought to be filled with liquid hydrocarbons, such as methane and ethane.
“With an average surface temperature hovering around -180 degrees C, water cannot exist on Titan except as deep-frozen ice as strong as rock,” Lopes said.
On Titan, methane takes water’s place in the hydrological cycle of evaporation and precipitation (rain or snow) and can appear as a gas, a liquid and a solid.
Methane rain cuts channels and forms lakes on the surface and causes erosion, helping to erase the meteorite impact craters that pockmark most other rocky worlds, such as our own Moon and the planet Mercury.
Yet more terrestrial-type features on Titan include dunes formed by cold winds, and mountain ranges.
These mountains might have formed tectonically when Titan’s crust compressed as it went into a deep freeze, in contrast to the Earth’s crust, which continues to move today, producing earthquakes and rift valleys on our planet.