Images from the Cassini mission show river networks draining into lakes in Titan's north polar region. Credit: NASA/JPL/USGS via MIT
Titan, a moon of Saturn, has been found to be an active mini-world of geological processes. But seeing those phenomena has been blocked by Titan’s thick, methane- and nitrogen-rich atmosphere.
Thanks to the Cassini-Huygens spacecraft mission supported by NASA and the European Space Agency, radar images and a landing probe have revealed a fascinating world.
Like here on Earth, plate tectonics, erupting volcanoes, advancing glaciers and river networks have all reshaped our planet’s surface over billions of years.
Now, according to researchers, similar processes on Titan may be at work: tectonic upheaval, icy lava eruptions, erosion and sedimentation by rivers.
While images of Titan have revealed its present landscape, very little is known about its geologic past. Now researchers at MIT and the University of Tennessee at Knoxville have analyzed images of Titan’s river networks and determined that in some regions, rivers have created surprisingly little erosion.
Why? It’s a head scratcher.
Possible causes
Two possible explanations: either erosion on Titan is extremely slow, or some other recent phenomena may have wiped out older riverbeds and landforms.
A paper detailing the new findings will appear in the Journal of Geophysical Research-Planets.
It’s pointed out that, compared to most moons in our solar system, Titan is relatively smooth – few craters pockmark its face.
One explanation is that Earth’s continents are always eroding or being covered with sediment. “That may be the case on Titan, too,” says Taylor Perron, the Cecil and Ida Green Assistant Professor of Geology at MIT.
Perron and MIT graduate student Benjamin Black set out to determine the extent to which rivers of liquid methane may have renewed Titan’s surface. The team analyzed images taken from Cassini-Huygens, and mapped 52 prominent river networks from four regions on Titan.
Weirdly Earth-like place
Black compared Titan’s images with recently renewed landscapes on Earth, including volcanic terrain on the island of Kauai and recently glaciated landscapes in North America.
The finding: The river networks in those locations are similar in form to those on Titan, suggesting that geologic processes may have reshaped the moon’s icy surface in the recent past.
Titan is “a weirdly Earth-like place,” even with this exotic combination of materials and temperatures, Perron says. “And so you can still say something definitive about the erosion. It’s the same physics.”
This research was supported by NASA’s Cassini Data Analysis Program.
For a video review of this Titan research, go to:
http://www.youtube.com/watch?v=Bx6kvL9Ia-I&feature=player_embedded#!
By Leonard David via Jennifer Chu, MIT News Office