Titan flyby

[Stargazer]

Cassini-Huygens did a recent flyby of one of the most interesting (in my opnion at least) moons, Titan. Old images from Voyager didn't show anything of the surface really, so it's very exciting to see some general features of Titan. It's very exciting to finally have this world revealed to us. The really good stuff should, if all goes well, be sent back to Earth from the Huygens probe which will descend through the thick atmosphere and land. It's even built to float for a while if it would land in, say, a liquid hydrocarbon ocean. It will also carry many scientific instruments, such as cameras and spectrometers, and some instruments to study the atmosphere itself - even a microphone. According to some sources, if we're really lucky we could pick up the sounds from thunder on an alien world. Ok, what's the word again? I think it's "wow". More links: http://saturn.jpl.nasa.gov/home/index.cfm, and http://www.esa.int/esaCP/SEMEIH0A90E_index_0.html

[BlameTheEx]

Those pictures are fantastic. Oh for just a little more detail. Do the features look volcanic to you, rather than metioric? Still, It looks like a solid surface.

[Stargazer]

The lighter areas seem like they could be rocky/icy, and the darker ones could be liquid. I also noticed a much brighter area, could it be a concentration of ice?

[BlameTheEx]

We may be looking at different images. Check this one.

 

http://saturn.jpl.nasa.gov/cgi-bin/gs2.cgi?path=../multimedia/images/titan/images/PIA06982.jpg&type=image

[Stargazer]

It looks more rocky than liquid, also the dark areas, except for the patch in the top of the image. I'm still guessing the dark areas is organic materials, and that the darkest patches could be liquid? I'm not sure at all... it's difficult to interpret these images. I suppose we will get to see more of Titan with more flybys.

[BlameTheEx]

This is what I am seeing.

 

A number of vertical cylinders, some white, with dark centres. Those centres make them look hollow. One at least appears to be ejecting thick black smoke. I have seen something like it before. Undersea volcanic vents, commonly called "Black Smokers."

 

If they are indeed what they look like to me, They are huge chimneys. That means rather slow non-violent ejection of minerals. Hot minerals. Quite possibly minerals from which energy can be extracted.

 

I hardly need to add that these are excellent conditions for life. Undersea volcanic vents are swarming with life that feeds on the energy rich minerals ejected.

 

A quote from this page:

http://www.onr.navy.mil/focus/ocean/habitats/vents1.htm

______________________________________________

In these areas, extremely hot, mineral-rich fluid flows out from underneath the ocean floor's surface. The hot fluid flows into very cold water, usually 2 C, and cools down quickly. The cooled minerals in the fluid settle around the vent opening creating chimney-like formations. Some chimneys have been known to grow as tall as 6 kilometers!

______________________________________________________

 

It would be interesting to speculate on what liquid is taking the place of the water of Earth's Black Smokers, or could the thick atmosphere be an acceptable substitute for liquid? Perhaps it IS water.

[Stargazer]

I don't really see the formations you see, what I see is some rocky features and dark liquid. I suppose we will know more soon.

[UncleAl]

This was the closest flyby, 745 miles altitude, to reshape Cassini's orbit by atmospheric drag. Official Truth will metamorphose from Titan being a giant ball of hydrocarbon resources to a big rock decorated with some photolytic organic goo. Do not despair! All that carbon plus subduction and tectonics means... HUGE diamonds!

 

The very large (N-15)/(N-14) ratio demands progressive atmospheric stripping by radiation and solar wind over cosmic times. Lighter isotope N-14 would be favored to depart vs. the heavier isotope. We should then see an even more extreme depletion in methane (CH4 MW=16.04 vs. N2 at 28.01) and hydrogen, and especially huge deuterium/hydrogen and (C-13)/(C-12) ratios. We also wonder why we don't see any chemically combined nitrogen species like hydrogen cyanide (HCN), cyanogen (NCCN), and acetonitrile, H3CCN. They saw diacetylene HCC-CCH.

 

Where you have hydrogen cyanide photochemistry you have diaminomaleonitrile and an efficient adenine factory. If you have nucleotides you have life. Titan is inhabited by by diamond-hoarding potentates eager for first contact. NASA crash fundng must be allocated...

[Stargazer]

Originally posted by: UncleAl

This was the closest flyby, 745 miles altitude, to reshape Cassini's orbit by atmospheric drag. Official Truth will metamorphose from Titan being a giant ball of hydrocarbon resources to a big rock decorated with some photolytic organic goo. Do not despair! All that carbon plus subduction and tectonics means... HUGE diamonds!

I wouldn't be so sure that huge diamonds, or even small ones, will be the result of the conditions on Titan...

 

The very large (N-15)/(N-14) ratio demands progressive atmospheric stripping by radiation and solar wind over cosmic times. Lighter isotope N-14 would be favored to depart vs. the heavier isotope. We should then see an even more extreme depletion in methane (CH4 MW=16.04 vs. N2 at 28.01) and hydrogen, and especially huge deuterium/hydrogen and (C-13)/(C-12) ratios. We also wonder why we don't see any chemically combined nitrogen species like hydrogen cyanide (HCN), cyanogen (NCCN), and acetonitrile, H3CCN. They saw diacetylene HCC-CCH.

 

Where you have hydrogen cyanide photochemistry you have diaminomaleonitrile and an efficient adenine factory. If you have nucleotides you have life. Titan is inhabited by by diamond-hoarding potentates eager for first contact. NASA crash fundng must be allocated...

My knowledge in the chemistry of Titan is limited it seems, and there hasn't been too much informationa bout it released to the public - at least to my knowledge, so I was wondering if you could give some useful links?

[Tormod]

Originally posted by: Stargazer

The lighter areas seem like they could be rocky/icy, and the darker ones could be liquid. I also noticed a much brighter area, could it be a concentration of ice?

 

 

I just attended a science seminar for the press hosted by the European Space Agency. The topic was the Cassini/Huygens mission and they discussed what they expect from the Huygens landing, and also discussed the pictures taken from Flyby A (ie, the one last week).

 

There are indeed very intriguing features on the surface, but the resolution is still way to low to be able to make out anything. The shades of gray do not tell us anything, and any color image is false color since the surface is not visible due to the haze (so they need to use infrared, and there are only 5 narrow bands in the spectrum in which the surface appears).

 

A specialist on planetary science explained how ice forms. He made a point which I had not given much thought: Water has the very strange property of being the only known molecule which, when solidified, floats in itself. So water ice tends to float in liquid water because the density of ice is lower than liquid water. Therefore, if there is any water on Titan, it will be frozen, and if there is any liquid water, it will be below the ice.

 

However, there can also be liquid ethane. Some have suggested oceans of MEthane, but methane only occurs naturally as a gas. Ethane is a favored candidate for oceans or lakes on Titan. Ethane, however, has a freezing point of -135 degrees Celsius, whereas the surface of Titan has an even temperature of -180 degrees Celsius.

 

So the chances for Huygens landing in liquid are, according to the guy I spoke with, equal to zero. (Sorry, I have the papers at my office and have forgotten his name - all I remember is that he was French and is responsible for the VIMS camera which took the photos of the Huygens landing site last week).

[Stargazer]

Originally posted by: Tormod

There are indeed very intriguing features on the surface, but the resolution is still way to low to be able to make out anything. The shades of gray do not tell us anything, and any color image is false color since the surface is not visible due to the haze (so they need to use infrared, and there are only 5 narrow bands in the spectrum in which the surface appears).

And add to that the problem that these infrared images can't show us any of the topography of the surface, for that they need to use radar, which they have recently done for some parts of the surface.

 

However, there can also be liquid ethane. Some have suggested oceans of MEthane, but methane only occurs naturally as a gas. Ethane is a favored candidate for oceans or lakes on Titan. Ethane, however, has a freezing point of -135 degrees Celsius, whereas the surface of Titan has an even temperature of -180 degrees Celsius.

I looked up the melting points of both ethane and methane, and they seem to be -182.76 C and -182.5 C respectively, according to Wikipedia. Since -180 C is the mean temperature of Titan's surface, isn't it then possible that there could be liquid methane and ethane?

[Tormod]

My bad. -135 C is the flash point. (That's what I get from sitting up too late...)

 

I am unable to provide the scientific background, I am just providing bits and pieces in the notes from the presentation.

 

The scientist in question was Christophe Sotin, from the laboratory of planetology and geodynamics (my translation from French), by the way, and his speech was titled "Titan's mystery: Oceans in the solar system".

 

He thinks there is an ocean on Titan, and that it may have a depth of somewhere between 100-300 kilometers. But the dense atmosphere and the temperature would form a solid surface widh a width of 50-150 kilometers. As of now I am unable to explain why he thinks so.

 

Methane does not appear as liquid in nature, AFAIK, whereas ethane does. Methane reacts easily with other chemicals, and one of the most well known sources for it is life, since methane is a byproduct of metabolism on Earth (maybe Tim_Lou can explain this better).

 

After all, one of the main tasks for the Huygens probe is to find out whether the surface has liquid or not, so I am only recounting one scientist's views. There are obviously a lot of theories around.

[Tormod]

Originally posted by: Stargazer

And add to that the problem that these infrared images can't show us any of the topography of the surface, for that they need to use radar, which they have recently done for some parts of the surface.

 

One of the other scientists at the seminar, (I think it was Roberto Orosei of the national astrophysics institute in Rome) had put together a "dummy" topology based on the observations they had and it appears that Titan may have very deep valleys, which "could hold oceans".

 

But - since there as of yet are no radar altimeter data he did not even propose any dimensions. On Europa the topology is about 10 meters from the low to the high point (AFAIK) so although his illustration was intriguing it really had no scientific value apart from being food for thought.

 

EDIT: They DID use radar and measure the topography in another project. Here is the link:

Topography on Titan

 

Quote from the text: "The data show a variation in height of only about 150 meters (490 feet) over the 400-kilometer-long (250-mile-long) track, indicating that in this region Titan is remarkably flat. "

[Tormod]

I really need to point out that my background here is a bit shaky so feel free to correct me if anything seems wrong. I have a stack of papers to read here in order to write some articles for the Norwegian Space Centre and I sitll haven't got the full picture (well, will I ever...).

[Stargazer]

Originally posted by: Tormod

 

He thinks there is an ocean on Titan, and that it may have a depth of somewhere between 100-300 kilometers. But the dense atmosphere and the temperature would form a solid surface widh a width of 50-150 kilometers. As of now I am unable to explain why he thinks so.

Still very interesting. I didn't know that they expected a solid surface instead of just liquid.

 

Methane does not appear as liquid in nature, AFAIK, whereas ethane does. Methane reacts easily with other chemicals, and one of the most well known sources for it is life, since methane is a byproduct of metabolism on Earth (maybe Tim_Lou can explain this better).

But shouldn't methane be in liquid form if the temperature is low enough? Anyway, you say it reacts easily, could this mean there is no "free" methane, or at least not much, on Titan for that reason?

 

After all, one of the main tasks for the Huygens probe is to find out whether the surface has liquid or not, so I am only recounting one scientist's views. There are obviously a lot of theories around.

Absolutely. Perhaps we know far too little to form a certain opinion yet. Huygens should cast more light on this mystery.

 

EDIT: They DID use radar and measure the topography in another project. Here is the link:

Topography on Titan

 

Quote from the text: "The data show a variation in height of only about 150 meters (490 feet) over the 400-kilometer-long (250-mile-long) track, indicating that in this region Titan is remarkably flat. "

Both Europa and Titan are very flat then. I suppose the surface is reshaped again and again by the gravitational pull of their respective gas giant planets? I would guess that Europa is so flat because of that but also because there might be liquid water underneath the cracked ice. Could Titan be somewhat similar in that there are oceans but with sold surfaces that are melted and refrozen repeatedly? I'm just guessing here...

[Tormod]

Originally posted by: Stargazer

But shouldn't methane be in liquid form if the temperature is low enough? Anyway, you say it reacts easily, could this mean there is no "free" methane, or at least not much, on Titan for that reason?

 

I think there is a lot of free methane gas in the athmosphere, plus a lot is bound into the ground in different phase stages. A lot of the methane will be bound up in hydrocarbons.

 

The origin of the methane is a mystery, though. It is one of the reasons scientists speculate that there may be life on Mars and Titan.

 

Both Europa and Titan are very flat then. I suppose the surface is reshaped again and again by the gravitational pull of their respective gas giant planets? I would guess that Europa is so flat because of that but also because there might be liquid water underneath the cracked ice. Could Titan be somewhat similar in that there are oceans but with sold surfaces that are melted and refrozen repeatedly? I'm just guessing here...

 

Yes, both moons appear to be very flat. For Europa's part I think it is due to the ice cover breaking up and fusing back together. This is apparent from the criss-crossing lines.

 

On Titan I think there might be some surprises. Maybe there is solid rock on the surface? I have seen calculations which suggest oceans up to 1,000 meters deep, but they are not necessarily global. This would not yet appear on any topology map since only the surface levels have been looked at, not possible ocean depth (AFAIK).

[BlameTheEx]

Oops, Double posted.