ON THE ABUNDANCES OF NOBLE-GASES ON THE SOLAR-SYSTEM PLANETS

Fractionation coefficients of gases with molecular masses M1 and M2 have been compared: In F(M1/M2) = (C(M1)/C(M2))planet/(C(M1)/C(M2))Sun. Logarithms of fractionation coefficients of any two gases depend linearly on the inverse ratio of molecular masses of these gases: F(M1/M2) = a (1-M2/M1). Furthermore, logarithms of fractionation coefficients of any two gases depend exponentially on the heliocentric radius of every planet. This dependence is revealed by connection of coefficient a with radius r: a = exp [alpha + beta/M2+(gamma/M2 + delta)/r]. These dependencies are semiquantitative for the solar system planets mentioned above, and allows one to predict correlations of noble gases for other planets, for example Mercury, and Jupiter. Common dependencies for all the planets point to the fact that present correlations of primary noble gases have been set in not during accretion of the planets, but early, probably during adsorption of the gases by matter-carrier of volatiles of the planets in a protoplanetary cloud.