Nick Matzke posted Entry 2474 on July 25, 2006 04:19 AM.
Trackback URL: http://www.pandasthumb.org/cgi-bin/mt/mt-tb.fcgi/2469

Lakes on Titan
July 24, 2006 Full-Res: PIA08630

The Cassini spacecraft, using its radar system, has discovered very strong evidence for hydrocarbon lakes on Titan. Dark patches, which resemble terrestrial lakes, seem to be sprinkled all over the high latitudes surrounding Titan’s north pole.

Scientists have speculated that liquid methane or ethane might form lakes on Titan, particularly near the somewhat colder polar regions. In the images, a variety of dark patches, some with channels leading in or out of them, appear. The channels have a shape that strongly implies they were carved by liquid. Some of the dark patches and connecting channels are completely black, that is, they reflect back essentially no radar signal, and hence must be extremely smooth. In some cases rims can be seen around the dark patches, suggesting deposits that might form as liquid evaporates. The abundant methane in Titan’s atmosphere is stable as a liquid under Titan conditions, as is its abundant chemical product, ethane, but liquid water is not. For all these reasons, scientists interpret the dark areas as lakes of liquid methane or ethane, making Titan the only body in the solar system besides Earth known to possess lakes. Because such lakes may wax and wane over time, and winds may alter the roughness of their surfaces. Repeat coverage of these areas should test whether indeed these are bodies of liquid.

No comment from me necessary, except I guess that I wasn’t completely wrong.

[Updated: I have moved the copious off-topic comments to the Bathroom Wall. Please talk about Titan, stealth figher anti-radar technology, and other related topics that are actually interesting.]

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Comment #114600

Posted by Andrew McClure on July 25, 2006 4:43 AM (e)

That is awesome.

Comment #114606

Posted by buddha on July 25, 2006 5:27 AM (e)

Andrew McClure wrote:

That is awesome.

Yeah, praise Jesus!

Comment #114609

Posted by Anonymous_Coward on July 25, 2006 6:00 AM (e)

buddha wrote:

Andrew McClure wrote:

That is awesome

Yeah, praise Jesus!

Why - is he going to turn the lakes into wine and capture and infinite amount of drunken fish?

Comment #114610

Posted by Peter Henderson on July 25, 2006 6:19 AM (e)

Some YEC organisation somewhere (probably AIG) will have an article which will claim “Lakes on Titan confirm creation (or a young solar system) !” or something similar !

I think astronomers did predict this though. Is there any evidence of waves ? This was a discussion topic in a recent Open University astronomy course that I did recently.

Comment #114612

Posted by Andrew McClure on July 25, 2006 6:31 AM (e)

Anonymous Coward wrote:

buddha wrote:

Andrew McClure wrote:

That is awesome

Yeah, praise Jesus!

Why - is he going to turn the lakes into wine and capture and infinite amount of drunken fish?

Can Jesus walk on liquid methane?

Comment #114615

Posted by Anonymous_Coward on July 25, 2006 6:53 AM (e)

Can Jesus walk on liquid methane?

WWJD?

Comment #114619

Posted by deadman_932 on July 25, 2006 7:27 AM (e)

MMMmmm…Slushies.

Comment #114631

Posted by Keith Douglas on July 25, 2006 8:10 AM (e)

That might be one greasy slushie …

Comment #114632

Posted by Laser on July 25, 2006 8:11 AM (e)

Some of the dark patches and connecting channels are completely black, that is, they reflect back essentially no radar signal, and hence must be extremely smooth.

Can someone explain to me why this is so? Very smooth surfaces reflect visible wavelengths well. Why is that not the case with radio waves?

Comment #114634

Posted by steve s on July 25, 2006 8:52 AM (e)

Comment #114615

Posted by Anonymous_Coward on July 25, 2006 06:53 AM (e) | kill

Can Jesus walk on liquid methane?

WWJD?

Does this mean What Was Jesus’s Density?

Comment #114635

Posted by Geoff Offermann on July 25, 2006 9:06 AM (e)

Laser: Can someone explain to me why this is so? Very smooth surfaces reflect visible wavelengths well. Why is that not the case with radio waves?

I think if they are black images this means that they reflect very well. This is counterintuitive, but it is the case as far as I can tell.

Comment #114638

Posted by Anonymous_Coward on July 25, 2006 9:10 AM (e)

Can someone explain to me why this is so? Very smooth surfaces reflect visible wavelengths well. Why is that not the case with radio waves?

I have no idea, so I’ll take a wild guess.

If something is very smooth, then the reflection should be perfect. That would mean you need to calculate the exact angle to get a reflection to a sensor. Rough surfaces would diffuse(?) the light, which would mean that we would have a better chance of receiving a reflected signal just from the diffused reflection alone.

Comment #114639

Posted by Anonymous_Coward on July 25, 2006 9:14 AM (e)

For example:

If you are in a darkened room with a mirror and you shine a light beam onto it at an angle, you would probably not see the mirror.

If instead the mirror was replaced by a piece of paper, you would probably be able to see the piece of paper because some of the roughness would reflect part of the beam back to you.

I’m guessing it would be much more exact in the real case since the lake seems to be large and would have a slight curvature to it.

But I’m just taking a wild wild guess.

Comment #114642

Posted by steve s on July 25, 2006 9:19 AM (e)

Specular vs Diffuse Reflection

Comment #114645

Posted by Anonymous_Coward on July 25, 2006 9:24 AM (e)

Okay, I tried to read it, but I think I have a reading problem.

How close was I?

Comment #114652

Posted by steve s on July 25, 2006 9:37 AM (e)

Comment #114645

Posted by Anonymous_Coward on July 25, 2006 09:24 AM (e) | kill

Okay, I tried to read it, but I think I have a reading problem.

How close was I?

Your explanation was very good.

Comment #114654

Posted by tacitus on July 25, 2006 9:39 AM (e)

You can tell the lakes are evidence of design by the way the shorelines are designed to maximize the amount of water–er, methane–front property.

Comment #114665

Posted by King Aardvark on July 25, 2006 10:16 AM (e)

WWJD = What Would Jesus Drink?

Comment #114685

Posted by K.E. on July 25, 2006 10:44 AM (e)

OK on the reflection thingy radio waves reflect off a flat conductive surface, such as sea water, almost perfectly.

However depending on the wavelength and the angle of incidence the reflection can be practically nil.

Allied bombers during WW2 used the lakes around Berlin with X-band H2S Radar (10Ghz /3cm ) as a guide to identify targets. The resolution of a 3cm wavelength radar is + or - a couple of wavelenths and a flat surface is plainly visable on a display weather it reflects or not, compared to rough surroundings.

The Germans when they discovered this quickly covered the lakes with antennas configured to reflect the signals (I’m guessing at different heights) so the lakes could not be used to guide the bombers.

Comment #114696

Posted by GuyeFaux on July 25, 2006 10:55 AM (e)

If something is very smooth, then the reflection should be perfect. That would mean you need to calculate the exact angle to get a reflection to a sensor. Rough surfaces would diffuse(?) the light, which would mean that we would have a better chance of receiving a reflected signal just from the diffused reflection alone.

Correct; this is why stealth fighters (F117) have no rounded surfaces. You would need to hit them at a very specific angle to bounce radar off of them.

Comment #114709

Posted by Glen Davidson on July 25, 2006 11:11 AM (e)

Correct; this is why stealth fighters (F117) have no rounded surfaces. You would need to hit them at a very specific angle to bounce radar off of them.

Stealth bombers do have curved surfaces, though. The difference is computing power, actually, because curves and rounding are fine just so long as they prevent reflections back to the radar sensors. F117s, as they say, look like a brick to radar, and they also fly like a brick. But the sharp angles were a good compromise between aerodynamics and being sure that radar would reflect “the wrong directions”.

I’m probably not telling you anything, just thought I’d try to clarify the matter more.

Glen D
http://tinyurl.com/b8ykm

Comment #114710

Posted by Nick Matzke on July 25, 2006 11:11 AM (e)

Regarding the lakes being black in the images, several people of figured it out, but here is a summary of why it works this way:

* The only “light source” for these images is the radar beams (= radio waves) that the Cassini satellite is shooting out.

* The satellite shoots out some radio waves, and then waits for the radar signal to bounce back. This signal is called backscatter.

* Backscatter depends on the chemical structure of materials but more importantly on the “roughness” of the surface. Rough surfaces will always have some surfaces directly perpendicular to the radio beam, which will bounce the signal directly back to the satellite

* Because the radar is being shot down to the surface at an angle, radar aimed at very smooth surfaces will “bounce away” from the satellite rather than bounce back to the satellite. Therefore low return is recorded for smooth surfaces, and when this is turned into image pixels smooth surfaces appear black.

(smooth surfaces are known as “specular”, i.e. mirrorlike)

In conclusion, these images mean that there are large specular reflectors down on Titan with lakelike shapes. It also may mean that there is not enough wind to produce much in the way of waves or “chop” (which radar can also detect under some circumstances). Placid hydrocarbon lakes evidently.

Comment #114717

Posted by Glen Davidson on July 25, 2006 11:17 AM (e)

As much evidence exists for the demise of evolution as exists for rational design in biology.

I like the struggle to stretch out the “inevitable collapse” of evolutionary theory. Apparently evolution happens rather more rapidly than evolutionary theory collapses.

Btw, “inevitable demise”, you apparently aren’t very bright, since you seem unable to differentiate between a post about evolution and one about Titan and its lakes.

Glen D
http://tinyurl.com/b8ykm

Comment #114727

Posted by Peter Henderson on July 25, 2006 11:26 AM (e)

Although this blog mostly deals with the biological arguments by creationists latest guise ID, YEC’s also deny things like stellar evolution. I often wonder how creationists like Dr Jason Lisle interpret Hertzsprung - Russell diagrams for example. If Dr. Lisle’s version of astronomy were to be adopted in American Universities (as AIG hopes will happen one day) would these become obsolete, since according to them stars don’t evolve. I’ve often wondered about that.

Comment #114755

Posted by Peter Henderson on July 25, 2006 12:02 PM (e)

All very good folks, but what has all this got to do with lakes on Titan ?

Comment #114773

Posted by end on July 25, 2006 12:45 PM (e)

And your presuppositions of antisupernaturalism are less than impressive.

Comment #114776

Posted by Bruce Thompson GQ on July 25, 2006 12:49 PM (e)

All very good folks, but what has all this got to do with lakes on Titan ?

PIA08448: Titan’s Land-o-Lakes

“The darkest areas could contain liquids, which tend to reflect the radar beam away from Cassini in the absence of winds, making the area appear quite dark. At Titan’s icy conditions, these liquids would be methane and/or ethane.”

Delta Pi Gamma (Scientia et Fermentum)

Comment #114792

Posted by Peter Henderson on July 25, 2006 1:47 PM (e)

Re #114776. More interesting photos Bruce. As I was saying, the OU course speculated about the existence of waves on these areas of liquid methane/ethane. As far as I can remember, there was also a prediction of Methane rain/snow. Can anyone confirm what type of weather (if any) is present on Titan ?

Comment #114793

Posted by Coin on July 25, 2006 1:48 PM (e)

This thread confuses me. Truly, it appears we have angered the Jupiterians.

Comment #114795

Posted by Peter Henderson on July 25, 2006 2:03 PM (e)

Re#114772: Just because we don’t know how life arose from no-life now doesn’t mean we’ll never know. At the moment it is beyond our understanding. However, there were many things that were meta-physics several hundred years ago which can now be explained by science.

I would hazard a guess that if we were able to physically able to explore every planetary body in the solar system, we would come across microbial life in quite a few of them, even in the most harshest of environments.

http://www.windows.ucar.edu/tour/link=/earth/Life/archaea.html

Comment #114798

Posted by Nick (Matzke) on July 25, 2006 2:26 PM (e)

Update: I have moved the copious off-topic comments to the Bathroom Wall. Please talk about Titan, stealth figher anti-radar technology, and other related topics that are actually interesting.

Comment #114799

Posted by jeannot on July 25, 2006 2:31 PM (e)

We’ve got a winner here. He even sounds more retarded than AFDave!

Just out of curiosity: how old is the Earth, Mr fanatic?

Comment #114800

Posted by fnxtr on July 25, 2006 2:38 PM (e)

Thanks, Nick, for scooping up the poop before I even got here. Makes for a much more pleasant/interesting read.

Comment #114833

Posted by Bruce Thompson GQ on July 25, 2006 4:10 PM (e)

Please talk about Titan

By describing the area as Titan’s “Land-o-Lakes” are the scientists suggesting that longer chain hydrocarbons also exist? If so then the pressing butter shortage on earth may have found an extraterrestrial solution.

Delta Pi Gamma (Scientia et Fermentum)

Comment #114840

Posted by Robert C on July 25, 2006 4:41 PM (e)

Anyone who is interested in a detailed summary of Titan’s chemistry can read this paper from the European Space Agency:
http://www.rssd.esa.int/SB/HUYGENS/docs/SP1177/raulin.pdf

The author suggests that UV light could create interesting products in the atmosphere, which would exist in aerosols, or precipitate. Liquid oceans might be very important for protecting the precipitated complex organics from UV photolysis, keeping them soluble, and allowing more chemistry. The accumulation of interesting organics in a ethane/methane sea seems pretty cool….

Comment #114844

Posted by whheydt on July 25, 2006 4:47 PM (e)

Ever since the possibility of liquids on the surface of Titan was raised, I’ve thought that any serious Titan lander should include a fishing pole. Who knows what might ‘bite’….

Comment #114854

Posted by Torbjörn Larsson on July 25, 2006 6:05 PM (e)

“such lakes may wax”

Such witticisms make me melt.

“Can anyone confirm what type of weather (if any) is present on Titan ?”

It seems to be cold with some liquid methane clouds and perhaps rain. If the sun wasn’t so weak, I would like to buy a beach property along one of those calm lakes. Googling I found these descriptions for example:

http://www.space.com/scienceastronomy/solarsystem/titan_weather_001020-1.html
http://www.astrobio.net/news/article1759.html
http://uanews.org/cgi-bin/WebObjects/UANews.woa/1/wa/MainStoryDetails?ArticleID=11870
http://www.esa.int/SPECIALS/Cassini-Huygens/SEMAXTMZCIE_0.html

Comment #114855

Posted by 'Rev Dr' Lenny Flank on July 25, 2006 6:08 PM (e)

How long before Exxon sends a probe to pump the lakes into a spaceship and carry it back here?

;>

Comment #114876

Posted by fnxtr on July 25, 2006 8:19 PM (e)

Lenny: … or just use it for fuel to go even farther.

Further?

Use it for further explorations.

Farther.

Never mind. It would be cool.

Comment #114881

Posted by 'Rev Dr' Lenny Flank on July 25, 2006 8:45 PM (e)

Lenny: … or just use it for fuel to go even farther.

And sell it to whom …. ?

;)

Comment #114896

Posted by Tice with a J on July 25, 2006 10:32 PM (e)

LAKES ON A MOON!

I can’t believe I’m the first person to make a “Snakes on a Plane” joke.

Comment #114900

Posted by steve s on July 25, 2006 10:59 PM (e)

We got Mothaf%cking Lakes on the Mothaf%cking Moon

Comment #114915

Posted by Anonymous_Coward on July 26, 2006 1:44 AM (e)

Ever since the possibility of liquids on the surface of Titan was raised, I’ve thought that any serious Titan lander should include a fishing pole. Who knows what might ‘bite’….

Considering the temperature of Titan… (isn’t Titan one of the coldest places in the Solar System?)

“I would like to go fishing and catch a fish stick. That would be convenient. You would only have to heat it up.” -Mitch Hedberg

Comment #114966

Posted by Michael Suttkus, II on July 26, 2006 10:25 AM (e)

Peter Henderson wrote:

…I often wonder how creationists like Dr Jason Lisle interpret Hertzsprung - Russell diagrams for example. If Dr. Lisle’s version of astronomy were to be adopted in American Universities (as AIG hopes will happen one day) would these become obsolete, since according to them stars don’t evolve.

I’ve never heard them address them directly, but I’d guess they would either run with Oomphalos (appearance of age) or take a cue from Walter ReMine and claim that a pattern, ANY pattern, is defacto evidence for a designer. This was the gist of his argument about the nested-hierarchy: It’s a pattern, therefore a designer must have caused it. Evolution involves randomness, therefore couldn’t produce a pattern!

Remember, kids, hurricanes swirl in a PATTERN. Every hurricane is a direct creative act by an intelligent designer: an intelligent designer who loves KILLING PEOPLE! I propose the Intelligent Designer of Hurricanes (IDoH) for the role of anti-god in for the Pastafarian religion.

Comment #114970

Posted by Unk on July 26, 2006 10:37 AM (e)

Can you see Rumfoord’s house?

Comment #114978

Posted by wamba on July 26, 2006 11:39 AM (e)

It’s cooler by the lake.

Comment #114998

Posted by Bruce Thompson GQ on July 26, 2006 3:27 PM (e)

Longer chain hydrocarbons are present in Titan’s atmosphere but oxygen exists only as a minor constituent limiting hopes of remedying the butter shortage.

Delta Pi Gamma (Scientia et Fermentum)

Comment #115036

Posted by Torbjörn Larsson on July 26, 2006 8:13 PM (e)

The weather report now also includes ice crystals, rainfall and fierce polar storms ( http://www.newscientistspace.com/article.ns?id=mg19125623.600&feedId=online-news_rss20 ).

Comment #115280

Posted by GuyeFaux on July 27, 2006 4:43 PM (e)

I wonder if Rachel Scwartz a.k.a. John Griffin a.k.a. all the other theorusts are trying to populate PT with this garbage so that in a year they can refer back to it and say “Look at all the controversy!”

I guess the hope is that the debunking/exposing will be lost over time.

Comment #115800

Posted by fnxtr on July 31, 2006 2:12 AM (e)

Tice with a J:

LAKES ON A MOON!

I can’t believe I’m the first person to make a “Snakes on a Plane” joke.

…and tonight around 5-ish I walked into the house and there were STEAKS ON A PLATE!!!!