Atmospheric Opacity - CERTIFIED
    Viking 1 July 26, 1976 (Ls 99.4 MY 12) to Nov 23, 1978 (Ls 180.4 MY 13)
    Viking 2 Sept 10, 1976 (Ls 120.5 MY 12) to Feb 22, 1979 (Ls 235.3 MY 13)































    This plot shows point-by-point Atmospheric Opacity measurements obtained by the Viking Landers during Mission Years 1 and 2, spanning sols 6-920 at VL1 and 6-872 at VL2. Link to the available data.


    The opacity data utilized Viking Lander camera images of the Sun to compute total normal atmospheric optical depth at the two landing sites over a period of about 900 Mars days. The optical depths were derived from Sun diode images, which were obtained by the Lander cameras at a wavelength of 0.67μ. For further information on the derivation and interpretation of this dataset see "Pollack, J.B., C.E. Carlston, D. Colburn, J. Hunter, R. Kahn, M.R. Wolf, and W. Van Kamp, Properties of Aerosols in the Martian Atmosphere, as Inferred From Viking Lander Imaging Data, Journal of Geophysical Research, 82, 4479-4496, 1977."

    Useful Mission Documents

    The Data The data description of the atmospheric opacity dataset describes the use of Viking Lander camera images of the Sun, taken at 0.67 μm, to compute total normal atmospheric optical depth at the two landing sites over a period of about 900 Mars days. This dataset contains 1044 measurements of optical depth and associated error estimates.

    Retrieving the Data Volume

    Viking 1 and 2 data file and labels are identified as vl_opac.dat, vl_opac.xml and vl_opac.lbl respectively. Both VL1 and VL2 opacity time histories are contained within a single file.

    Citing Datasets for Publication

    Colburn, D.S., VL1/VL2-M-LCS-5-ATMOS-OPTICAL-DEPTH-V1.0, NASA Planetary Data System, 1989.