Accession Number : AD0700840

Title :   ESTIMATE OF RADIOGENIC He4 AND Ar40 CONCENTRATION IN THE CYTHEREAN ATMOSPHERE,

Corporate Author : LOCKHEED MISSILES AND SPACE CO PALO ALTO CALIF LOCKHEED RESEARCH LAB

Personal Author(s) : Knudsen,William C. ; Anderson,Albert D.

Report Date : 25 JUL 1969

Pagination or Media Count : 4

Abstract : Mixing ratios for He4 and Ar40 in a 100% Co2 Mariner 5 model of the Cytherean lower atmosphere are derived by assuming that the He4 and Ar40 are secondary in origin and result entirely from radioactive disintegration with subsequent outgassing from the planet. Production rates on Venus are assumed equal to those for the earth. Thermal escape of He4 is shown to be negligible, and other loss mechanisms are assumed unimportant. Concentration of these gases in the upper atmosphere of Venus are calculated from the mixing ratios and a turbopause at 6180 km radius. (Author)

Descriptors :   (*VENUS(PLANET), *PLANETARY ATMOSPHERES), HELIUM, ARGON, ABUNDANCE, RADIOACTIVE DECAY, CARBON DIOXIDE

Subject Categories : Astrophysics

Distribution Statement : APPROVED FOR PUBLIC RELEASE