Titan Occupies A Solar System Sweet Spot

SocietyoftheFist writes "From an article on the BBC website, scientists have determined that Titan occupies a 'sweet spot' much like Earth. Venus is the same size as Earth but too hot so water boiled off long ago ending most geologic processes. Mars is too small to generate enough heat to keep water from freezing so it too slowed down geologically. Titan is much like the Earth with winds, rains and tectonic forces but instead of water it has an abundance of methane. Methane is liquid at the temperatures found in Titan's atmosphere and replaces water in the equation."

Re:methane?

[Tango42]

Methane only burns in the presence of oxygen, there's not enough oxygen on Titan for that. You'll have to go back to mailboxes.

Re:methane?

[dreamchaser]

There are theoretical models which postulate that life 'not quite as we know it' could evolve in a methane based ecosystem.

Article lacks accuracy?

[VoidWraith]

In both of their "sweet spot" scenarios, they attribute boiling water to solar proximity, but then frozen water to planetary mass. In both cases, the whole thing can be explained just with solar proximity, as it usually has been. Planets farther away have colder temperatures. Yes, its true that a smaller planet will retain less heat, but the primary factor here is still solar proximity.

Methane doesn't replace water.

[caveat]

While the methane jokes are just HI-larious, on a more serious/sci-nerd note:

Methane is a lot less likely to be the "solvent" for life as water is. Water has a lot of very unusual properties which are important factors in the biochemical reactions of life; the most important of these is its strong polar nature. The polarity of water is a, if not the (biochemists feel free to correct me, i'm synthetic org.), major factor in protein folding; the ability of water to dissolve ionic compounds is also vitally important, e.g. nerve function. Bottom line, a nonpolar organic solvent is a *lot* less likely, if not impossible, to support life.

Re:Speed

[frgough]

Chemical reactions for life go too slowly at our temperature, too, and thank goodness they do or we would all chemically react ourselves into a pile of goo in a matter of a few minutes.

You want reactions that are slow, but that can be sped up using a catalyst when necessary. That allows you to control the reactions and switch them on and off as needed. In biological systems enzymes are the catalysts.

Re:Methane doesn't replace water.

[suchire]

It isn't just polarity; hydrogen bonding plays a huge part in creating the entropic effects necessary for protein folding, as well as the optimal heat capacity for maintaining a stable earth temperature.

Methane ice worms living on Earth

[kevin777]

Maybe we should be looking for some life forms similar to these: Methane Ice Worms [wikipedia.org]

Image here. [psu.edu]

Text:

Methane clathrate deposits in the ocean floor have been found to be inhabited by polychaete worms of the species Hesiocaeca methanicola. The worms colonize the ice-methane solid and appear to survive by gleaning bacteria that in turn metabolize the clathrate. In 1997, Charles Fisher, professor of biology at Penn State, discovered this remarkable creature living on mounds of methane ice under half a mile of ocean on the floor of the Gulf of Mexico.

Re:methane?

[Anonymous Coward]

The reaction is:
CH4 + 2O2 = CO2 + 2H2O

sheesh

Re:you

[ikkonoishi]

And to extract it from the water ice you need fire to melt the ice and electricity to seperate the oxygen.

It takes 118 kcal to turn two H20 molecules into one 02 molecule (I'm ignoring the hydrogen as waste for the moment.)

You need two O2 molecules to react with one molecule of methane. This reaction will produce
191.6826 kcal.

Which means that it would take a net energy input of 44 kilocalories per each molecule of methane that you burn.

You better make that a large fire to start with because it will only get smaller the more you use it.

Re:Sure about Venus?

[lorelorn]

Venus would probably be habitable if it had an earth-like rotation. But it turns so slowly that a day is slightly longer than a year.

The additional heat that it receives from the sun, combined with that length of exposure to it, meant temperatures soared.

The atmosphere is mainly Sulphur Dioxide. The planet has been wrought with volcanism in the past, so much so that the whole surface is about the same age.

Any water Venus may have had is long gone.

The thick atmosphere acts as a blanket, trapping the heat it receives from the sun, basically making the planet is its own pressure cooker. Every so often, it must 'boil over' in a colossal volcanic episode.