Detection of Molecular Oxygen on Mars

Molecular oxygen was detected in martian spectra near 7635 angstroms and its abundance measured both during and after the 1971 dust storm. Its column abundance in the clear martian atmosphere is about 10.4 � 1.0 centimeters amagat, giving a mixing ratio of molecular oxygen to carbon dioxide of 1.3 x 10-3. The mixing ratio of molecular oxygen to carbon monoxide (1.4 � 0.3) is quite different from the value of 0.5 that would result from the photolysis of a pure carbon dioxide atmosphere, which indicates that there is or was a net source of oxygen relative to carbon (probably water) in the martian atmosphere.

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

[2]  R. Goldstein,et al.  Mars Radar Observations, a Preliminary Report , 1971, Science.

[3]  A. Kliore,et al.  Mariner 9 S-Band Martian Occultation Experiment: Initial Results on the Atmosphere and Topography of Mars , 1972, Science.

[4]  C. Hord,et al.  Mariner Ultraviolet Spectrometer: Topography and Polar Cap , 1971, Science.

[5]  A. Lane,et al.  Mariner 9 Ultraviolet Spectrometer Experiment: Initial Results , 1972, Science.

[6]  R. Schlapp,et al.  Fine Structure in the 3 Σ Ground State of the Oxygen Molecule, and the Rotational Intensity Distribution in the Atmospheric Oxygen Band , 1937 .

[7]  M E Davies,et al.  Mariner 9 Television Reconnaissance of Mars and Its Satellites: Preliminary Results , 1972, Science.

[8]  A E Rogers,et al.  Martian Craters and a Scarp as Seen by Radar , 1971, Science.

[9]  D. Hunten,et al.  Erratum: a Search for O_{2} on Mars and Venus: a Possible Detection of Oxygen in the Atmosphere of Mars , 1968 .

[10]  I. Clark.  The Chemical Kinetics of CO2 Atmospheres , 1971 .

[11]  M. McElroy,et al.  Dissociation of CO2 in the Martian Atmosphere , 1971 .

[12]  Dudley A. Williams,et al.  Broadening of Infrared Absorption Lines at Reduced Temperatures, II. Carbon Monoxide in an Atmosphere of Carbon Dioxide† , 1972 .

[13]  L. Young,et al.  Interpretation of high resolution spectra of Mars—III. Calculations of CO abundance and rotational temperature , 1971 .

[14]  L. Giver,et al.  Intensity measurements and rotational intensity distribution for the oxygen A-band , 1969 .

[15]  V. Oinas,et al.  Atmospheric Radiation , 1963, Nature.

[16]  D. Hunten.  Composition and structure of planetary atmospheres , 1971 .

[17]  L.D.Gray Young,et al.  Interpretation of high resolution spectra of Mars—II calculations of CO2 abundance, rotational temperature and surface pressure , 1971 .

[18]  D. E. Burch,et al.  Strengths, Widths, and Shapes of the Oxygen Lines near 13,100 cm(-1) (7620 A). , 1969, Applied optics.

[19]  J. Margolis,et al.  High dispersion spectroscopic studies of Mars. V - A search for oxygen in the atmosphere of Mars. , 1971 .

[20]  L. Kaplan,et al.  Carbon monoxide in the Martian atmosphere. , 1969 .