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Titan's Tropical Weather
Hugh Pickens writes "Climate researchers Ray Pierrehumbert and Jonathan Mitchell at the University of Chicago say that Titan, the only moon in the solar system large enough to support an atmosphere, has many of the same weather features as Earth, but with completely different substances that work at temperatures that plunge down to minus 170 degrees Celsius. Pierrehumbert and Mitchell call Titan's climate 'tropical,' a climate that is warm to hot and wet year-round, because on Titan methane assumes the role of water and exists in enough abundance to condense into rain and form puddles on the surface. Titan's tropical nature means that scientists can observe the behavior of its clouds using theories they've developed to understand Earth's tropics. For example, Titan's atmosphere produces an updraft where surface winds converge to lift evaporated methane up to cooler temperatures and lower pressures, where much of it condenses and forms clouds, 'a well-known feature on Earth called an ITCZ, the inter-tropical convergence zone,' Mitchell says."
Har har, but no, it wouldn't. Methane is odorless. That's why gas companies have to include additives with natural gas, so leaks can be detected.
The Gish Bar Times - Blog covering Jupiter's moon Io
It is nice to see a climate model that adds in the information we have gleaned from the equatorial deserts on Titan. Much of the equatorial dark terrain on Titan is covered in sand dunes (made of organics, rather than quartz sand) while the bright material near the equator looks very much like the desert US southwest, with large mesas carved by the action of flowing methane, suggestive of short-duration, but high-volume, rain showers at equatorial latitudes. Much of the climate studies done recently have focused on the weather at the poles, were the majority of large clouds systems, lakes, and seas have been observed.
The Gish Bar Times - Blog covering Jupiter's moon Io
Fortunately for most of us, the clock on our desktops are the only way we're keeping track of time. (It's always dark in the basement you know)
IMHO, Planetary time (or moon time, etc) is the least of our concerns when considering a habitable planet.
I think the GP concern of "days" is the length of when you have light, not temperature. I don't think it's that much of a concern though because there would be so much less light anyway. I think the "nights" where Titan is closer to the Sun might even be brighter than "days" because you get the diffuse reflection of sunlight off of Saturn. The times where the moon is behind Saturn are going to be extremely dark though.
I'd have to disagree -- people live in different areas of the earth where days are of vastly different lengths. And while it's not super healthy, many people live on all manner of strange day cycles with artificial light. I have read that without any clues as to time, people don't naturally settle into a 24 hour day anyways, and that in fact they vary their sleeping cycles longer and shorter over time.
:)
On the other hand, low gravity wreaks havoc with bones and blood vessel walls and such. Hot and cold we can control pretty well, so that's not a huge concern, though it certainly makes it more expensive. Radiation and such may also be a concern for planets without a strong magnetic field. And then there's the whole sustainable artificial ecosystem thing we've yet to work out to any real degree
Overall I think living on another planet is going to be a lot harder than we generally expect. We take for granted how well adapted we are to the specifics of planet Earth, and how much we depend on millions of other things that are also well adapted for the specifics of planet Earth. As someone suggested: it would be much easier to build a colony on the bottom of Earth's ocean than another planet, but we haven't even done that yet because it's cost prohibitive and the benefits aren't clear.
But we'll get there someday, I suppose!
Cheers.
Many cold worlds exhibit cryovolcanism. Some cold moons are also experiencing tidal forces. Some worlds may have underground oceans. Sun is not the only source of energy out there. There is kinetic energy as well, and cryovolcanism, tidalism, oceans, and geoactivity may provide it in abundance.
It looks like self-reproducing molecules on Earth have been successful in utilising every form of energy they could find, even in harsh underground environments. With such a determination to live and reproduce, I think that some molecules on a cold world could utilise kinetic energy to sustain their reproduction.
I realize it's probably a joke, but we've got frozen methane hydrate, underwater, here on Earth. There was one quote that said that if the moon had gold bricks for the taking it would still be a major loss to collect them. At Titan? Forget it.
Something about that comment being modded "insightful" vs "funny" scares me.
Faster! Faster! Faster would be better!
Although living cells are *mostly* carbon, hydrogen, and oxygen, several other elements are indispensable to life.
And you won't get very far without iron and/or some other transition element that you can use to push electrons around to catalyze reactions. I'm not thinking hemoglobin but rather oxidative phosphorylation/electron transport chains or some xenobiochemical equivalent.
The other problem is that life on earth thrives because we are able to create a "barrier" between the polar world around us by using phospholipids. That way we can divide the world into "the water outside the cell" and "the water inside the cell", and then control the "inside" to our liking.
In a methane world, where your solvent will presumably be some organic substance, instead of water: what do you use as an relatively impermeable barrier? Personally I'd love to see organisms with crystalline cell walls, however I imagine growth and reproduction would be a bitch.
Seven puppies were harmed during the making of this post.