Titan flyby

[BlameTheEx]

Tormod

 

Did the guess in my last post get considered in any form?

[Tormod]

There was some mention of hot vents, but they are not likely to appear on Titan because of the way the different layers of the crust seem to be composed. The non-liquid scientist suggested that there is a layer of ice, followed by a liquid (these would be H2O or at least ethane and water), followed by what he called High Pressure ice which is heavier than water and thus sinks. After that comes the sulfate layer which forms the seafloor. Since the thickness of each layer is very thick, he did not think it was a possibility for hot vents on Titan, but he thought it was very likely on Europa.

[Stargazer]

Originally posted by: 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.

Could it be that the methane on both Mars and Titan comes from underground deposits? Or would such a process have depleted the planets of most methanes already? Life is of course the most exotic theory for the presence of methane, and I really hope that is the case. It would show us that a planet doesn't have to be in the traditional "habitable zone" to harbor life.

 

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).

I hope they are planning on doing radar mapping of most of the Titan's surface, to bring some light over that moon. I hope more missions to Saturn will follow soon... but it seems to go painfully slow, the exploration of the solar system.

[Tormod]

Originally posted by: Stargazer

I hope they are planning on doing radar mapping of most of the Titan's surface, to bring some light over that moon. I hope more missions to Saturn will follow soon... but it seems to go painfully slow, the exploration of the solar system.

 

They will do a lot of things - and considering there are at least 44 Titan flybys with Cassini I think we will know a lot more about Titan than we do now.

 

Yes, the exploration is slow. But remember that it has taken 25 years (!) from the initial idea of a Saturn mission until it is finally realized. Just the travel stage has taken 7 years.

 

The sad thing is that as far as I know there is not a single new mission for the outer solar system in development...

[Tormod]

Originally posted by: Stargazer

Could it be that the methane on both Mars and Titan comes from underground deposits? Or would such a process have depleted the planets of most methanes already?

 

If it does NOT come from underground deposit we have a problem, because at least on Mars the methane is washed away by the solar wind as soon as it leaves the ground. The only other possible source for methane on Mars is volcanic activity, which is not currently known to exist...so the methane must come from *somewhere* underground.

 

On Titan the same problem exists. In the outer layers of the athmosphere the methane is swept away by the solar winds and while the depletion rate is slower than on Mars, it would be gone in less time than Titan has existed. So it is a mystery where all the methane comes from, and why it is still there.

[Stargazer]

Originally posted by: Tormod

They will do a lot of things - and considering there are at least 44 Titan flybys with Cassini I think we will know a lot more about Titan than we do now.

I hope the Huygens probe does its job well, too, so that we can finally figure out exactly what is underneath that atmosphere. Rocks, ice, hydrocarbon lakes, frozen lakes, dirty snow?

 

Yes, the exploration is slow. But remember that it has taken 25 years (!) from the initial idea of a Saturn mission until it is finally realized. Just the travel stage has taken 7 years.

25 years is almost as long as I have lived! How frustrating. Is this because the space programme is, in my view, horribly underfunded and in lack of real political support? I mean, NASA gets like 16 billion each year lately, and next year, the military funding will be 482 billion, according to a proposal. What if humankind could shape up and do the exact opposite? But, maybe that's a rant better suited for the Philosophy section... Anyway, with proper funding, and enough people working on several missions, we could see a NASA (and ESA, etc.) do wonders in space. We could see a swarm of space probes examining the planets and the moons, with people to follow.

 

The sad thing is that as far as I know there is not a single new mission for the outer solar system in development...

 

Jupiter Icy Moons Orbiter

New Horizons (Pluto)

 

So there are a few projects being worked on, but I would like to see dedicated spacecrafts to Neptune and Uranus as well.

[Tormod]

The New Horizons is a compromise after the Kuiper mission was cancelled by NASA to due budget reasons, but it is nevertheless a very interesting mission. The icy moons thing won't lanuch for at least another then years.

 

I completely agree with you - there is so much potential for cooperation between NASA and ESA. Cassini/Huygens is a prime example, as is the work on the International Space Station. I too would love to see a "swarm" of small satellites swooping all over the place...

[BlameTheEx]

It's looking like Titan's surface is mostly solid and geologically active

 

Articles on pictures, and radar maps of Titan:

 

http://www.newscientist.com/news/news.jsp?id=ns99996652

http://www.nasa.gov/mission_pages/cassini/media/cassini-102904.html

 

All pictures and radar maps from Cassini-Huygens:

http://www.nasa.gov/mission_pages/cassini/media/Cassini_Multimedia_Collection(Search_Agent)_archive_1.html