Beneath the mask, Titan looks surprisingly smooth and youthful

Jul 27, 2012 By Jenny Winder, Universe Today
Caption: Images from the Cassini mission show methane river networks draining into lakes in Titan’s north polar region. Credit: NASA/JPL/USG

Saturn’s largest moon, Titan has long been hidden beneath the thick shroud of its methane- and nitrogen-rich atmosphere. That all changed in 2004 when NASA’s Cassini mission was able to penetrate the haze and sent back detailed radar images of the surface. These showed an icy terrain, carved over millions of years, by rivers similar to those found here on Earth. However, Titan’s surface doesn’t look as old and weather-beaten as it should. The rivers have caused surprisingly little erosion and there are fewer impact craters than would be expected. So what is the secret to Titan’s youthful complexion?

Titan is around four billion years old, roughly the same age as the rest of the solar system. But the low number of impact craters put estimates of its surface at only between 100 million and one billion years old.

Researchers at MIT and the University of Tennessee at Knoxville have analyzed images of Titan’s river networks and suggest two possible explanations: either erosion on Titan is extremely slow, or some recent phenomena has wiped out older surface features.

Taylor Perron, the Cecil and Ida Green Assistant Professor of Geology at MIT explains, “It’s a surface that should have eroded much more than what we’re seeing, if the river networks have been active for a long time. It raises some very interesting questions about what has been happening on Titan in the last billion years.”

Perron suggests that geological processes on Titan may be like those we see here on Earth. Here too, impact craters are scarce, as plate tectonics, erupting volcanoes, advancing glaciers and river networks reshaped our planet’s surface over billions of years, so, on Titan, tectonic upheaval, cryovolcanic eruptions, erosion and sedimentation by rivers could be altering the surface.

Discovering which processes are at work is not easy. The images from Cassini are like aerial photos but with much coarser resolution. They are flat, with no information about a surface elevation or depth.

Perron and MIT graduate student Benjamin Black analyzed the images and mapped 52 prominent river networks from four regions on Titan. They then compared the images with a model of river network evolution developed by Perron. Their data depicts the evolution of a river over time, taking into account variables such as the strength of the underlying material and the rate of flow through the river channels. As a river erodes, it transforms from a long, spindly thread into a dense, treelike network of tributaries. Titan’s river networks have maintained their long and spindly composition. They compare with recently renewed landscapes here including volcanic terrain on the island of Kauai and recently glaciated landscapes in North America.

Besides Earth, Titan is the only world with an active hydrologic cycle forming active river networks. ’s surface temperature may be about 94 K and its rivers run with liquid methane but as Perron says “It’s a weirdly Earth-like place, even with this exotic combination of materials and temperatures, and so you can still say something definitive about the erosion. It’s the same physics.”

Below is a video of Black and Perron explaining their research:

This video is not supported by your browser at this time.


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Lurker2358
5 / 5 (4) Jul 27, 2012
Couple issues:

1, Natural abundance Methane is slightly lighter at the atomic scale than natural abundance water, therefore less gravitational potential.

2, Surface gravity 7.3 times smaller than Earth, greatly reducing gravitational potential, therefore Erosion should be at least 7.3 times slower than on Earth at least for same minerals vs same minerals.

3, Water molecules have a partial charge since they are not symmetrical along one of their axis, i.e. the bent shape between Hydrogen atoms, this allows water to dissolve or suspend particles even in an otherwise chemically neutral environment. The same is not true of liquid Methane.

4, Titan's distance from the Sun means far less energy input to do work.

So all told, I'd expect that if you had the same size feature on Earth as Titan, and it was similar mineralogy, then it would probably take at least ten times longer, possibly 20 or more times longer, to erode the same feature on Titan as on Earth.
kevinrtrs
1 / 5 (5) Jul 27, 2012
Lurker, Fair enough, I had some similar thoughts on it. I think the ultra low temperature might also result in possible "frozen" ground which might also impede erosion.
Unfortunately, even when all is added up, it still doesn't explain why the erosion is so visibly absent after supposedly billions of years had passed.
That leaves researchers with a nice headache to explain why it is that way.
Coupled to the low cratering count, plus existence of an equatorial lake which should have evaporated long ago, it becomes even more challenging given that there is no current machine on the surface to present more data. Right now, the only effect is that Titan looks young.
gwrede
not rated yet Jul 27, 2012
There are other dissimilarities, too.

On Earth, much of river erosion is caused by sand particles, not the water itself. They float or roll in the liquid, scratching the riverbed. These sand particles originate from rock erosion originally by temperature differences between night and day, which on Titan are much smaller. Also, we have all kinds of organisms that erode rock.

Also, rock is made of much more diverse and complicated molecules than water. This makes rock, although it is hard, more susceptible to erosion.

Erosion is further speeded up by impurities in the fluid and the ground, both of which may be largely missing on Titan. That is, what if it really is only water ice and methane ethane, without calcium, sulphur, sodium, etc.?

There are no thick clouds, so rain is actually minimal on average.

So, one should rather expect a huge difference in erosion rate!
Lurker2358
not rated yet Jul 27, 2012
After further thought, erosion rate should be directly proportional to solar and tidal inputs, in most cases except faulting and large land slides.

Gravitational potential merely provides a means of storage of thermal energy input (through convection and precipitation).

The solar inputs is about 100 times smaller than for the earth, and so about 6/7ths of the thermal energy on Titan is coming from tidal forces and internal heat, perhaps radio-isotopes or left over accretion heating.

So at any rate, the total thermodynamic potential on Titan may be as little as 100 times smaller than the Earth,which is quite honestly pathetic. There's more energy coming from the CFL light bulb over my head than the per-meter solar constant at Titan...

So over all, you wouldn't expect much erosion on Titan at all. It should pretty much sit there at nearly time-stop conditions, except when directly following being impacted by a large meteor or something like that...
Torbjorn_Larsson_OM
3 / 5 (2) Jul 27, 2012
Creationists shouldn't comment on science, it is hilarious! Of course Titan doesn't erode as easily as Earth, given (and see earlier comments too):

- The gravity potential is much less on Titan.
- The thermal energy is much less on Titan.
- Water is much more aggressive than methane, being a polar as opposed to non-polar liquid which electrostatically react with any surface. Further, water is an ampholyte, act as both an acid and a base by giving off (H2O -> OH- H ) or accept (H2O H -> OH3 ) protons. This makes it nearly impossible to avoid chemical erosion.

Nevertheless it will be interesting to see why there is another young surface in the system, akin to parts of Venus, the whole Earth, parts of Mars, Europa et cetera, given that we know the methane has been there for nearly 0.5 billion years at the most.

Creationists can't explain that because according to them all bodies should look equally young, and no planets or moons should be the observed 4.5 billion years.
Torbjorn_Larsson_OM
3 / 5 (2) Jul 27, 2012
[cont]

They reason why they are here instead of over at the posts on research on how entropy in crowded environments create order is that it throws a large and for them unexplainable monkey wrench into the creationist machinery for disfiguring entropy: entropy =/= disorder. [ http://phys.org/n...res.html ]

We know that figure of speech is wrong, but now we have explicit examples of systems that break it. (Self-assembling systems like micelles and lipid protocell membranes are strictly not fully due to entropy forces.)

Of course Earth has an energy source, the same energy source that at the far distance of Titan drives a weaker erosion, so we don't expect that thermodynamical machines like refrigerators can't create some loose concept of "order". But it turns out that even in a closed system we can have increased order.

And creationists wonder why we laugh at them and their anti-science "science" especially!?
Lurker2358
1 / 5 (3) Jul 27, 2012
Torbjorn_Larssen:

I am a creationist, idiot.

You mad? I correctly described all the reasons before anyone else on here even bothered to respond, except Kevin.

You mad?

And you are wrong. Technically the Bible does not state directly that everything is the same age, in fact "stars and planets(aka 'wandering stars')" are created on a different "day" than the Earth itself, or light, for example.

We know that figure of speech is wrong, but now we have explicit examples of systems that break it.


Actually, we don't. If you are referring to that article from a few days ago, the scientists failed to calculate the net entropy caused by the very "act" of adding new particles. Which is to say, they had a "closed" system, but only partially. Any time you add to a system entropy is created. The entropy created by this action would be greater than the order created inside the container.

Isaac Newton, who discovered the law of Entropy, was a creationist.

You mad he beat atheists to it
Lurker2358
1.7 / 5 (6) Jul 27, 2012
Atheists shouldn't comment on science, or math for that matter.

After all, the majority of the formalized, fundamental work in both fields for at least the past 3500 years has come from creationists, mostly of the Abrahamic faiths, but also Egyptian, Babylonian, and Greek.

The formalized proof of Pythagorean theorem is greek, but it was known to Jews, Egyptians, and Babylonians centuries, even at least 2 millennia ahead of time.

Optics, gravity, thermodynamics and other force laws, and formal equations and formal proofs? Isaac Newton, a strict creationist and Bible scholar.

The first combustion engine and pressure pumps? Muslim, Jewish, and Babylonian inventors in Egypt and Babylon...such that the technology was later lost for nearly 2000 years.

Relativity? A Jewish deist.
Electricity? A deist with Christian background and theology degree.
The Big Bang theory? A practicing Roman Catholic.

Nearly every fundamental science with practical daily use was discovered by a creationist..
Jack Shyte
1 / 5 (3) Jul 27, 2012
LOL...
You guys are hilarious... :)

I have only one question that is really got me wondering
what would happen if all that methane & nitrogen was to be ignited??
could it ignite in that enviroment?
Anorion
2 / 5 (4) Jul 28, 2012
LOL...
You guys are hilarious... :)

I have only one question that is really got me wondering
what would happen if all that methane & nitrogen was to be ignited??
could it ignite in that enviroment?

-jack shyte

no oxygen no combustion
Husky
not rated yet Jul 28, 2012
actually nasa is pondering an airbreathing plane for in the thick titan atmosphere, it would have to bring its own oxygen tank though...
SatanLover
1 / 5 (1) Jul 28, 2012
i see the inquisition is starting to pick their pace up... sigh..
ubavontuba
2 / 5 (4) Jul 28, 2012
This looks so much like an Earthly topographical map that it makes me wonder ...are fish swimming in those streams?

What a weird, but strangely familiar, place...

Titan's catch of the day: Frozen Fish Sticks. Yummy.

A father swimming in Titan's lakes would be a "pop-sicle."

Titan cows would give icecream.

To drive a car on Titan, you'd have to fill the tank with oxygen!

"Fill 'er up with premox3, Al. Thanks."
Lurker2358
5 / 5 (2) Jul 28, 2012
actually nasa is pondering an airbreathing plane for in the thick titan atmosphere, it would have to bring its own oxygen tank though...


A pointless waste when a hydrogen or Helium balloon requires no fuel at all and should provide massive buoyant force in the thick Titan atmosphere when compared to it's paltry gravity.
alfie_null
5 / 5 (1) Jul 29, 2012
Nearly every fundamental science with practical daily use was discovered by a creationist.

You are confusing creationism with theism. Also note that in some (maybe most) of the cited cultures, there was no religious freedom.

Atheists shouldn't comment on science, or math for that matter.

False analogy. Using your examples, arguing against inclusion of women, or non-whites also works.
nuge
not rated yet Jul 30, 2012
Lurker, I agree with everything you said in your first comment, but I'm absolutely sure the researchers would have thought of all those things and taken them into account.
dzipo
1 / 5 (1) Jul 31, 2012
Let's say that erosion is much slower. Then why we don't see craters? Isn't it erosion that makes craters disappear on Earth?

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