Removal of Titan's noble gases by their trapping in its haze

Titan's haze, formed by photolysis of C2H2, C2H4 and HCN, was found experimentally to trap Ar, Kr and Xe with efficiencies of 3.5 x 10(-4), 1.9 x 10(-3) and 6.5 x 10(-2) [noble gas atom]/[carbon atom] in the polymer, respectively. The rate of aerosol formation and settling down of 3 x 10(-13) kg m(-2) s(-1), as inferred from our experiments on CH4 photolysis in the far UV [Podolak, M., Bar-Nun, A., 1979. Icarus 39, 272-276], is sufficient to reduce the mixing ratios of Ar-36 and Ar-40 to their low values of (2.8 +/- 0.3) x 10(-7) and (4.3 +/- 0.1) x 10(-3), respectively, and those of Kr and Xe to below the detection limit of 10(-8). (c) 2008 Elsevier Inc. All rights reserved.