Friday, April 22, 2005

Titan Resurfacing through Biothermal Energy?

Linked above is a paper brought to my attention yesterday. In this paper by Dirk Schulze-Makuch and David H. Grinspoon, the authors suggest that heating produced by organisms near Titan's surface could explain the relatively youthful surface of Titan. Their contention is that organisms could have evolved in hot springs and in temporary crater H2O lakes, and later may have evolved to survive on Titan's surface, metabolizing photochemically produced acetylene. The heat from chemical reactions produced by the organisms, the authors posit, could then be enough to produce the energy needed for the cryovolcanism observed by RADAR.

Personally, I feel there are a number of problems with the arguments in this paper. First, the environments suggested for the development of life are fairly limited in extent but yet the authors require life to be fairly widespread for their heating mechanism to work. They get around this by suggesting the life could have evolved to survive the surrounding terrain, but I would think that much of the energy it produced would go toward not just running the reactions that keep it going, but to also keep the water in its body from freezing. I can buy the alternative metabolic pathways argument just based on the diversity seen on Earth, but the requirement to keep its body from freezing, let alone have enough excess heat to power volcanoes, seems to be a brick wall for life to overcome.

2 Comments:

Blogger Bruce Moomaw said...

Both Schulz-Makuch and Grinspoon, unfortunately, have a tendency for rather wild-eyed speculations as to just how much extraterrestrial life elsewhere in the Solar System may be capable of -- something they've shown in the past regarding Europa and Venus, respectively. (One may regard this as "astrobiological wishful thinking".) Sometimes a really weird idea turns out to be true, of course -- but it usually doesn't.

I myself think the heat driving Titan's cryovolcanism is tidally induced by that moon's surprisingly eccentric orbit -- and I suspect Bruce Bills and Francis Nimmo are right in their recent speculation that it's being kept eccentric by resonant gravitational tuggings which come in Titan's case (unlike Io's) not from other moons, but from Jupiter itself during its periodic close encounters with Saturn. They haven't worked out all the details of this theory yet, but it seems to me to fit the now-known facts better than any other so far:

http://www.lpi.usra.edu/meetings/lpsc2004/pdf/1341.pdf

4/23/2005 03:04:00 AM  
Anonymous Gsnorgathon said...

Jupiter... is there anything it can't do?

4/24/2005 02:47:00 PM  

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