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Hamill CD, Chabot NL, Mazarico E, Siegler MA, Barker MK, Martinez Camacho JM. New Illumination and Temperature Constraints of Mercury's Volatile Polar Deposits. THE PLANETARY SCIENCE JOURNAL 2020; 1:57. [PMID: 33210087 PMCID: PMC7668200 DOI: 10.3847/psj/abb1c2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Images from the Mercury Dual Imaging System (MDIS) aboard the MErcury Surface, Space ENvironment, GEochemistry, and Ranging mission reveal low-reflectance polar deposits that are interpreted to be lag deposits of organic-rich, volatile material. Interpretation of these highest-resolution images of Mercury's polar deposits has been limited by the available topography models, so local high-resolution (125 m pixel-1) digital elevation models (DEMs) were made using a combination of data from the Mercury Laser Altimeter (MLA) and from shape-from-shading techniques using MDIS images. Local DEMs were made for eight of Mercury's north polar craters; these DEMs were then used to create high-resolution simulated image, illumination, and thermal models. The simulated images reveal that the pixel brightness variations imaged within Mercury's low-reflectance deposits are consistent with scattered light reflecting off of topography and do not need to be explained by volatile compositional differences as previously suggested. The illumination and thermal models show that these low-reflectance polar deposits extend beyond the permanently shadowed region, more than 1.0 km in some locations, and correspond to a maximum surface temperature of greater than 250 K but less than 350 K. The low-reflectance boundaries of all eight polar deposits studied here show a close correspondence with the surface stability boundary of coronene (C24H12). While coronene should only be viewed as a proxy for the myriad volatile compounds that may exist in Mercury's polar deposits, coronene's surface stability boundary supports the idea that Mercury's low-reflectance polar deposits are composed of macromolecular organic compounds, consistent with the hypotheses of exogenous transport and in situ production.
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Affiliation(s)
- Colin D Hamill
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA
| | - Nancy L Chabot
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA
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Golish DR, Drouet d'Aubigny C, Rizk B, DellaGiustina DN, Smith PH, Becker K, Shultz N, Stone T, Barker MK, Mazarico E, Tatsumi E, Gaskell RW, Harrison L, Merrill C, Fellows C, Williams B, O'Dougherty S, Whiteley M, Hancock J, Clark BE, Hergenrother CW, Lauretta DS. Ground and In-Flight Calibration of the OSIRIS-REx Camera Suite. SPACE SCIENCE REVIEWS 2020; 216:12. [PMID: 32025061 DOI: 10.1007/s11214-017-0460-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 11/27/2019] [Indexed: 05/29/2023]
Abstract
The OSIRIS-REx Camera Suite (OCAMS) onboard the OSIRIS-REx spacecraft is used to study the shape and surface of the mission's target, asteroid (101955) Bennu, in support of the selection of a sampling site. We present calibration methods and results for the three OCAMS cameras-MapCam, PolyCam, and SamCam-using data from pre-flight and in-flight calibration campaigns. Pre-flight calibrations established a baseline for a variety of camera properties, including bias and dark behavior, flat fields, stray light, and radiometric calibration. In-flight activities updated these calibrations where possible, allowing us to confidently measure Bennu's surface. Accurate calibration is critical not only for establishing a global understanding of Bennu, but also for enabling analyses of potential sampling locations and for providing scientific context for the returned sample.
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Affiliation(s)
- D R Golish
- 1Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | | | - B Rizk
- 1Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - D N DellaGiustina
- 1Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - P H Smith
- 1Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - K Becker
- 1Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - N Shultz
- 1Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - T Stone
- United States Geological Survey Astrogeology Science Center, Flagstaff, AZ USA
| | - M K Barker
- 3Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, MD USA
| | - E Mazarico
- 3Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, MD USA
| | - E Tatsumi
- 4Department of Earth and Planetary Science, The University of Tokyo, Tokyo, Japan
| | - R W Gaskell
- 5Planetary Science Institute, Tucson, AZ USA
| | - L Harrison
- 1Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - C Merrill
- 1Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - C Fellows
- 1Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - B Williams
- 1Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - S O'Dougherty
- 1Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - M Whiteley
- 6Space Dynamics Laboratory, Utah State University, Logan, UT USA
| | - J Hancock
- 6Space Dynamics Laboratory, Utah State University, Logan, UT USA
| | - B E Clark
- 7Department of Physics and Astronomy, Ithaca College, Ithaca, NY USA
| | - C W Hergenrother
- 1Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - D S Lauretta
- 1Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
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Golish DR, Drouet d’Aubigny C, Rizk B, DellaGiustina DN, Smith PH, Becker K, Shultz N, Stone T, Barker MK, Mazarico E, Tatsumi E, Gaskell RW, Harrison L, Merrill C, Fellows C, Williams B, O’Dougherty S, Whiteley M, Hancock J, Clark BE, Hergenrother CW, Lauretta DS. Ground and In-Flight Calibration of the OSIRIS-REx Camera Suite. SPACE SCIENCE REVIEWS 2020; 216:12. [PMID: 32025061 PMCID: PMC6979463 DOI: 10.1007/s11214-019-0626-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 11/27/2019] [Indexed: 05/18/2023]
Abstract
The OSIRIS-REx Camera Suite (OCAMS) onboard the OSIRIS-REx spacecraft is used to study the shape and surface of the mission's target, asteroid (101955) Bennu, in support of the selection of a sampling site. We present calibration methods and results for the three OCAMS cameras-MapCam, PolyCam, and SamCam-using data from pre-flight and in-flight calibration campaigns. Pre-flight calibrations established a baseline for a variety of camera properties, including bias and dark behavior, flat fields, stray light, and radiometric calibration. In-flight activities updated these calibrations where possible, allowing us to confidently measure Bennu's surface. Accurate calibration is critical not only for establishing a global understanding of Bennu, but also for enabling analyses of potential sampling locations and for providing scientific context for the returned sample.
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Affiliation(s)
- D. R. Golish
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | | | - B. Rizk
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | | | - P. H. Smith
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - K. Becker
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - N. Shultz
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - T. Stone
- United States Geological Survey Astrogeology Science Center, Flagstaff, AZ USA
| | - M. K. Barker
- Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, MD USA
| | - E. Mazarico
- Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, MD USA
| | - E. Tatsumi
- Department of Earth and Planetary Science, The University of Tokyo, Tokyo, Japan
| | | | - L. Harrison
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - C. Merrill
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - C. Fellows
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - B. Williams
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - S. O’Dougherty
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - M. Whiteley
- Space Dynamics Laboratory, Utah State University, Logan, UT USA
| | - J. Hancock
- Space Dynamics Laboratory, Utah State University, Logan, UT USA
| | - B. E. Clark
- Department of Physics and Astronomy, Ithaca College, Ithaca, NY USA
| | | | - D. S. Lauretta
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
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