Why Does Titan Have Fewer Impact Craters?

[LumenPlacidum]

I've been looking around for information on Saturn's moon, Titan, to present to my class. One thing that wikipedia seems to say about the moon is that it has distinctly fewer impact craters than other moons of its size and position in the solar system. Supposedly, this is attributed to some combination of atmospheric shielding and the idea that it must have a relatively young surface.

It doesn't seem to me that we can possibly conclude that the surface of Titan is young. On Earth, we seem to have relatively few impact craters. In part, this is due to atmospheric shielding, but the other major factor (at least, in my mind--and this is what I'm after) is erosion. Am I missing something? Couldn't Titan, which has a dense atmosphere (and so, its wind would have significant force) and which supposedly has a fluid cycle on its surface and in its atmosphere, have a lack of impact craters simply because they've been disintegrated by powerful erosion?

I'm hoping to start a conversation on this. I don't really know if my reasoning is flawed, based on incorrect or incomplete information or what.

 

[Radrook]

You are right, erosion does contribute significantly to Titan's topography. That's what makes it's surface young. The term "young" in geology simply means that the surface has been subjected to "recent erosion" via impact cratering, wind, rain, volcanic flows, etcetera.

Y
young
When used to describe a planetary surface, "young" means that the visible features are of relatively recent origin, i.e. that older features have been destroyed by erosion or lava flows. Young surfaces exhibit few impact craters and are typically varied and complex; in contrast, an "old" surface is one that has changed relatively little over geologic time. The surfaces of Earth and Io are young; the surfaces of Mercury and Callisto are old.
http://www.solarviews.com/eng/terms.htm

Here are some suggested reasons for fewer visible signs of crater-impacts on Titan.

1. Erosion via liquid methane rain and the flows.
2. Wind, and wind-driven sand [BTW: Titan's dunes are made of solid hydrocarbons that that turn to grains after raining down from the atmosphere..]
3. Cryovolcanism? [as yet unconfirmed]
4. Coverage of craters by wind-driven sand dunes.
5. Thick atmosphere shielding the surface from larger impacts.

Scientists Puzzled by Titan's Missing Craters
http://www.bibliotecapleyades.net/luna/esp_lunassistsolar_titan02.htm

A New Crater for Titan
August 29, 2011
... Titan's dense atmosphere burns up the smaller impacting bodies before they can reach the surface. The craters that do form are often hard to recognize or disappear entirely as they are eroded over time by geological processes such as the wind-driven motion of sand and, possibly, icy volcanism...
Credit: NASA/JPL-Caltech

http://saturn.jpl.nasa.gov/photos/imagedetails/index.cfm?imageId=4354

Far too few
http://www.bibliotecapleyades.net/luna/esp_lunassistsolar_titan02.htm

Also, because the surface was detected by the Cassini Orbiter as shifting nineteen miles in three years, Titan's crust is thought to be resting on liquid. The swift shifting is said to be aided by the wind-pressure against Titan's mountains much as a sail on a ship.

The Moon's Entire Crust May Slide Over Subsurface Ocean
Titan's surface was shifting by 0.36 degrees per year. For there to be this rapid of a shift in the position of Titan's surface requires the surface to be able to move freely about the rest of the moon, sliding around atop a liquid interior ocean.

http://planetary.org/news/2008/0320_When_Titans_Winds_Blow_Mountains.html

Signs of Hidden Ocean Underneath Titan's Crust
Slippage in Titan's rotation suggests water between its surface and core—and a higher likelihood of ancient life on Saturn's biggest moon


Last year, researchers reported that radar mapping of Titan by the Cassini spacecraft had found a peculiar shift in landmarks on the moon's surface of up to 19 miles (30 kilometers) between October 2004 and May 2007.


http://www.scientificamerican.com/article.cfm?id=signs-of-hidden-ocean-under-titans-crust

 

[davenn]

and do forget the other major contributer on Earth for a young surface is plate tectonics


Dave

 

[Radrook]

and do forget the other major contributer on Earth for a young surface is plate tectonics


Dave

Not just for Earth but it is also evident on Titan.

Tectonics on Titan

A set of three parallel ridges was seen by the Cassini spacecraft 's radar instrument during the latest Titan flyby on May 12, 2008. This combination is unlikely to be a coincidence -- the best explanation for these features is that they are tilted or separated blocks of broken or faulted crust, now exposed as high ridges. Their regular spacing is typical of regions that have been compressed or extended over large areas; as an example, the western United States Basin and Range Province was formed by extension. Such interactions are called tectonics, although they do not happen in the same way as plate tectonics, which is a process unique to Earth.

http://www.nasa.gov/mission_pages/cassini/multimedia/pia10654.html

Titan, moon of Saturn
Titan, the largest moon of Saturn, was reported to show tectonic activity in images taken by the Huygens Probe, which landed on Titan on January 14, 2005.[71]
http://en.wikipedia.org/wiki/Plate_tectonics

BTW

I find Titan far more interesting than Mars.

 

[Gliese123]

BTW

I find Titan far more interesting than Mars.

Me too! And more interesting than Europa actually even though it's interesting also.

 

[Phoenix59]

Would you say it's possible that another reason for the lack of impact craters on Titan might be Saturn's mass pulling meteors and asteroids into its gravity well?

I suppose that effect would be even more pronounced with Jupiter if this were the case.