Composition of the Atmosphere at the Surface of Mars: Detection of Argon-36 and Preliminary Analysis

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Science  27 Aug 1976:
Vol. 193, Issue 4255, pp. 801-803
DOI: 10.1126/science.193.4255.801


The composition of the martian atmosphere was determined by the mass spectrometer in the molecular analysis experiment. The presence of argon and nitrogen was confirmed and a value of 1 to 2750 ± 500 for the ratio of argon-36 to argon-40 was established. A preliminary interpretation of these results suggests that Mars had a slightly more massive atmosphere in the past, but that much less total outgassing has occurred on Mars than on Earth.

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