Monday, July 30, 2012

Is Radiocarbon Dating Possible on Titan?

  Would the equilibrium condition for C-14 in the atmosphere work on Titan? The solar wind extends out to Saturn and we know that Saturn has aurorae. Titan has a nitrogen atmosphere, there is a source of carbon in the form of methane, CH4, and there appears to be hydrocarbon lakes on the surface. So we would expect a source of C-14 and some carbon sinks. But is this enough?
  The lighter gravity causes the atmosphere to extend farther out from the surface than on Earth and as a result its surface pressure ends up slightly greater than that of the Earth. The solar wind particle density at Saturn is 0.1 per cm2 while on Earth the value is somewhat larger at 6 per cm2. As a result the production rate of C-14 is probably less on Titan. On the other hand, like the Moon, Titan's rational rate is the same as its orbital rate, 16 days, with a small inclination of its axis and its year is 29.5 Earth years. As a result one would expect the rate associated with carbon sinks to be less than that of the Earth. So it is possible that there is a measurable quantity of C-14 in Titan's atmosphere. But it may not be as stable as the quantity on the Earth since there are longer time scales associated with the fluctuations for the source and drain. The deviation between C-14 times and calendar times may as a result be much larger on Titan.
  So if Titan could support life that utilizes atmospheric methane one might be able to obtain a C-14 date for some remnant and compare this with dates for layers caused by annual deposits. For more accurate carbon dating an ocean world such as Earth might be necessary.

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