Methane rain possible on Titan (APOD 2 Aug 2006)

[orin stepanek]

http://antwrp.gsfc.nasa.gov/apod/ap060802.html
Pretty good art. Not too far out from the few pictures of Titan from Huygen's probe. I wonder what forms of life could exist in such an environment?
Orin

[johnnyc8]

I have a question. How is lightning even possibly possible on Titan? The APOD explanation says that lightning is "possible". From what I understand methane is an outrageously flammable substance and lightning is one of the best ignition sources known in the solar system. If one bolt of lightning struck Titan, a world with immense amounts methane, would not the whole planet just go up in flames?

I probably do not understand because I do not understand Titan's environment or do not understand enough about the characteristics of liquid methane. Any help would be appreciated.

[aichip]

Without free oxygen, the methane cannot ignite. Lightning would be perfectly safe, and if it is present, would explain the dark stuff in the bottoms of the rivers and lakes.

Lightning would polymerize methane into petroleum sludge over time. The process is called hydrogen reformation.

[Qev]

I've heard proposals for theoretical organisms based on methane-hydrogen metabolisms, much like the methanogenic bacteria that live here on Earth (including in the human gut ). I daresay they wouldn't be like our methanogens, since they'd need to be adapted to cryogenic conditions.

[rigelan]

If you want a chemical equation:: (I didn't feel like balancing it)

CH4 (methane) + O2 (Oxygen gas) ->
CO2 (Carbon Dioxide) + H2O (Water) + Energy

If you are missing one of the reactants (CH4 or O2), then you will not get any of the prducts (CO2, H2O, energy) unless you can get them through some other means.

[dcmcp]

....methane is an outrageously flammable substance...

In a methane atmosphere, free oxygen is by necessity rare. So to a native of Titan Oxygen is the flammable substance (since Oxygen burns in a methane atmosphere).

[harry]

Hello All

Aichip said that methane hit by lighting forms a oil product. I wander if earth went through a methane evolution.

That reminds, at the bottom of the oceans don't we have lots of methane, or some form of hydrocarbon in solid state.

Must look it up on google.

[orin stepanek]

Hi Harry! Methane liquefies at about -162C so solid methane would make the bottom of the ocean pretty cool
I bet the fish on Titan would have pretty thick skin.
Orin

[Qev]

Yup, Harry, along the continental edges of the sea floor here on Earth, we have huge deposits of clathrates, also known as methane hydrates. You can find pictures of the stuff online, it's very peculiar: it looks very much like white ice. Amusingly, it's ice that, if you touch a match to it, will burn and melt at the same time (the heat breaks down the clathrate, producing water and methane gas, which promptly burns).

On a tangental note, these clathrates are a possible risk in the global warming scenario. If the ocean temperatures rise by even a relatively small amount, the clathrates can break down, triggering a massive release of methane, which is a very potent greenhouse gas, possibly leading to a sort of accelerating feedback loop of global warming. Unpleasant thought.

Titan could probably use some global warming though.

dcmcp: Regarding oxygen and a methane atmosphere, from a chemistry standpoint 'burning' is the process of rapid, exothermic oxidation (loss of electrons), so oxygen itself never technically burns, since it's the one gobbling up the electrons. But I'm just picking nits.

[orin stepanek]

Hi Qev! sounds like clathrates could be a good source of energy; but more research need to be done in releasing the methane from this ice. Nice find.
Orin

[harry]

Hello Qev


Smile
Did you spell yep wrong as yup or is that how you say over there in the land of milk and honey.

Here in ozzzz we have more bees.

Thanks for the info on methane.

There are talks of mining this for energy. I saw it on the discovery channel.

[Qev]

There are definitely proposals for mining clathrates as a source of fuel! But getting down to them is tricky, as is mining them on large scales safely. Clathrate deposits have also been implicated in causing tsunami, as when they become buried by large amounts of sediment, the pressure and heat cause them to disassociate, triggering undersea landslides (the source of many large tsunami).

I think most Canadians (but the East-Coasters) say 'yup'. I'm being a bad Canadian and dropping all the 'eh's at the ends of my sentences, though.

[harry]

Hello Qev

Clathrate deposits have also been implicated in causing tsunami

I did know this. Thanks qev