Chromaticity of the Martian sky as observed by the Mars Exploration Rover Pancam instruments

[1] We have derived quantitative color estimates of the Martian sky from data acquired by the Panoramic Cameras (Pancams) on the Mars Exploration Rovers Spirit and Opportunity. We calculate the perceptual color of the sky directly from the absolute radiometric calibration of the cameras, following similar approaches to those used in previous studies with Viking Lander and Mars Pathfinder data. We further use these measurements to study changes in sky color throughout the MER missions and to compare these to changes in atmospheric opacity determined from direct solar imaging by the Pancams. We have derived a functional relationship between sky color and optical depth and discuss its possible uses and limitations. Finally, we simulate changes in sky color as suspended dust is removed and present visual representations of these based on modeling results, past studies, and observed MER sky brightnesses. The color of the Martian sky as opacity decreases from 1.0 to 0.0 is estimated to change from “dark yellowish brown” at high opacity to “bluish-black” or “black” if dust-free.

[1]  Gunther Wyszecki,et al.  Color Science: Concepts and Methods, Quantitative Data and Formulae, 2nd Edition , 2000 .

[2]  R. J. Reid,et al.  Mineralogic and compositional properties of Martian soil and dust: Results from Mars Pathfinder , 2000 .

[3]  S. T. Elliot,et al.  Mars Exploration Rover Athena Panoramic Camera (Pancam) investigation , 2003 .

[4]  Raymond E. Arvidson,et al.  The Martian surface as imaged, sampled, and analyzed by the Viking landers , 1989 .

[5]  R. Arvidson,et al.  Nature and distribution of surficial deposits in Chryse Planitia and vicinity, Mars , 1988 .

[6]  Richard W. Zurek,et al.  Interannual variability of planet-encircling dust storms on Mars , 1993 .

[7]  Amitabha Ghosh,et al.  First Atmospheric Science Results from the Mars Exploration Rovers Mini-TES , 2004, Science.

[8]  T. McCord,et al.  Spectral Reflectance of Martian Areas during the 1973 Opposition: Photoelectric Filter Photometry 0. 33-1. 10 μm , 1977 .

[9]  R E Arvidson,et al.  Three Mars Years: Viking Lander 1 Imaging Observations , 1983, Science.

[10]  F. O. Huck,et al.  Spectrophotometric and color estimates of the Viking Lander sites , 1977 .

[11]  A. Dollfus,et al.  Telescopic observations - Visual, photographic, polarimetric. [of planet Mars] , 1992 .

[12]  L. Soderblom.  The composition and mineralogy of the Martian surface from spectroscopic observations: 0.3 μm to 50 μm. , 1992 .

[13]  K. Stamnes,et al.  Numerically stable algorithm for discrete-ordinate-method radiative transfer in multiple scattering and emitting layered media. , 1988, Applied optics.

[14]  M. Shepard.  The Bloomsburg University Goniometer (B.U.G.) Laboratory: An Integrated Laboratory for Measuring Bidirectional Reflectance Functions , 2001 .

[15]  J. Pollack,et al.  Properties and effects of dust particles suspended in the Martian atmosphere , 1979 .

[16]  G. R. Gladstone,et al.  A new model for Mars atmospheric dust based upon analysis of ultraviolet through infrared observations from Mariner 9, Viking, and Phobos , 1995 .

[17]  William H. Farrand,et al.  Overview of the Spirit Mars Exploration Rover Mission to Gusev Crater: Landing site to Backstay Rock in the Columbia Hills , 2006 .

[18]  J. Pollack,et al.  Martian global dust storms: Zonally symmetric numerical simulations including size‐dependent particle transport , 1993 .

[19]  Jimmy D Bell,et al.  Atmospheric Imaging Results from the Mars Exploration Rovers: Spirit and Opportunity , 2004, Science.

[20]  Richard W. Zurek,et al.  An analysis of the history of dust activity on Mars , 1993 .

[21]  R. Todd Clancy,et al.  Mars aerosol studies with the MGS TES emission phase function observations: Optical depths, particle sizes, and ice cloud types versus latitude and solar longitude , 2003 .

[22]  Mark T. Lemmon,et al.  Properties of dust in the Martian atmosphere from the Imager on Mars Pathfinder , 1999 .

[23]  J. Maki,et al.  The color of Mars: Spectrophotometric measurements at the Pathfinder landing site , 1999 .

[24]  Miles J. Johnson,et al.  In‐flight calibration and performance of the Mars Exploration Rover Panoramic Camera (Pancam) instruments , 2006 .

[25]  C. Sagan,et al.  Secular changes and dark-area regeneration on Mars , 1967 .

[26]  B. Duval.  Commission internationale de l’éclairage (CIE) , 2001, Optique Photonique.

[27]  R. Todd Clancy,et al.  Constraints on the size of Martian aerosols from Thermal Emission Spectrometer observations , 2003 .

[28]  D. Ming,et al.  Pancam Multispectral Imaging Results from the Opportunity Rover at Meridiani Planum , 2004, Science.

[29]  D. Ming,et al.  Pancam Multispectral Imaging Results from the Spirit Rover at Gusev Crater , 2004, Science.

[30]  J. Bell.  Charge-coupled device imaging spectroscopy of Mars: 2. Results and implications for Martian Ferric mineralogy , 1992 .

[31]  Jimmy D Bell,et al.  Absorption and scattering properties of the Martian dust in the solar wavelengths. , 1997, Journal of geophysical research.

[32]  J. Bell,et al.  1995 observations of Martian dust storms using the Hubble Space Telescope , 1996 .