The composition of the atmosphere at the surface of Mars

We have confirmed the discovery of N2 and 40Ar by the Entry Science Team, and we have also detected Ne, Kr, Xe, and the primordial isotopes of Ar. The noble gases exhibit an abundance pattern similar to that found in the terrestrial atmosphere and the primordial component of meteoritic gases. Xenon appears to be underabundant in comparison to the meteoritic ratio, as it is on earth. The isotopic ratios 15N/14N, 40Ar/36Ar, and 129Xe/132Xe are distinctly different from the terrestrial values, implying different evolutionary histories for volatiles on the two planets. The noble gas abundances indicate that at least 10 times the present atmospheric amount of N2 and 20 times the CO2 abundance were released by the planet during geologic time; the outgassing of a large amount of water must also have taken place. There is thus an explanation for the high surface pressure and abundance of water required at some early epoch to cut the dendritic channels observed on the Martian surface.

[1]  T. Owen,et al.  Mars and Earth: Origin and Abundance of Volatiles , 1977, Science.

[2]  S. Rasool,et al.  Implications of the Viking results for volatile outgassing from Earth and Mars , 1977, Nature.

[3]  A. T. Young,et al.  Interpretation of high-resolution spectra of Mars. IV - New calculations of the CO abundance , 1977 .

[4]  D. R. Rushneck,et al.  The Atmosphere of Mars: Detection of Krypton and Xenon , 1976, Science.

[5]  D. R. Rushneck,et al.  The Atmosphere of Mars near the Surface: Isotope Ratios and Upper Limits on Noble Gases , 1976, Science.

[6]  D. R. Rushneck,et al.  Search for Organic and Volatile Inorganic Compounds in Two Surface Samples from the Chryse Planitia Region of Mars , 1976, Science.

[7]  M. McElroy,et al.  Isotopic Composition of the Martian Atmosphere , 1976, Science.

[8]  A. Nier,et al.  Isotopic Composition of Nitrogen: Implications for the Past History of Mars' Atmosphere , 1976, Science.

[9]  K. Biemann,et al.  Composition of the Atmosphere at the Surface of Mars: Detection of Argon-36 and Preliminary Analysis , 1976, Science.

[10]  A. Nier,et al.  Composition and Structure of the Martian Atmosphere: Preliminary Results from Viking 1 , 1976, Science.

[11]  F. Fanale.  Martian volatiles - Their degassing history and geochemical fate , 1976 .

[12]  J. Levine.  A new estimate of volatile outgassing on Mars , 1976 .

[13]  T. Owen.  Volatile Inventories on Mars , 1976 .

[14]  T. Owen.  Martian climate: an empirical test of possible gross variations. , 1974, Science.

[15]  Charles A. Barth,et al.  The Atmosphere of Mars , 1974 .

[16]  D. J. Milton.  Water and processes of degradation in the Martian landscape , 1973 .

[17]  F. Fanale,et al.  ORIGIN OF PLANETARY PRIMORDIAL RARE GAS: THE POSSIBLE ROLE OF ADSORPTION. , 1972 .

[18]  Duwayne M. Anderson,et al.  Mass spectrometric analysis of organic compounds, water and volatile constituents in the atmosphere and surface of Mars: The Viking Mars Lander , 1972 .

[19]  M. McElroy.  Mars: An Evolving Atmosphere , 1972, Science.

[20]  F. Fanale.  History of Martian volatiles: Implications for organic synthesis☆ , 1971 .

[21]  J. Geiss,et al.  Apollo 11 and 12 solar wind composition experiments: Fluxes of He and Ne isotopes , 1970 .

[22]  M. McElroy,et al.  Mars: Is Nitrogen Present? , 1970, Science.

[23]  D. Heymann,et al.  Noble gases in carbonaceous chondrites , 1970 .

[24]  G. Anderson,et al.  Mariner 6: Ultraviolet Spectrum of Mars Upper Atmosphere , 1969, Science.

[25]  L. Young.  Interpretation of high resolution spectra of Mars. II , 1969 .

[26]  E. Alexander,et al.  Terrestrial abundance of noble gases , 1968 .

[27]  T. Owen.  The Composition and Surface Pressure of the Martian Atmosphere: Results from the 1965 Opposition , 1966 .

[28]  H. D. Holland.  On the Chemical Evolution of the Terrestrial and Cytherean Atmospheres , 1964 .

[29]  J. H. Reynolds.  DETERMINATION OF THE AGE OF THE ELEMENTS , 1960 .

[30]  William Walden Rubey,et al.  Development of the Hydrosphere and Atmosphere, with Special Reference to Probable Composition of the Early Atmosphere , 1955 .

[31]  D. Heymann.  The Inert Gases , 1950, Nature.