Thermophysical Diversity of Young Lunar Crater Ejecta Revealed with LRO Diviner Observations
Young (<1 Ga) craters on the Moon are known to host diverse mixtures of ejecta with varying spectral and physical properties. In this work, we examine 13 yr of bolometric surface temperature data from the Diviner Lunar Radiometer on board the Lunar Reconnaissance Orbiter over the ejecta blankets...
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2024-01-01
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| Series: | The Planetary Science Journal |
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| Online Access: | https://doi.org/10.3847/PSJ/ad84e3 |
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| author | Cailin L. Gallinger Jean-Pierre Williams Catherine D. Neish Tyler M. Powell Catherine M. Elder Rebecca R. Ghent Paul O. Hayne David A. Paige |
| author_facet | Cailin L. Gallinger Jean-Pierre Williams Catherine D. Neish Tyler M. Powell Catherine M. Elder Rebecca R. Ghent Paul O. Hayne David A. Paige |
| author_sort | Cailin L. Gallinger |
| collection | DOAJ |
| description | Young (<1 Ga) craters on the Moon are known to host diverse mixtures of ejecta with varying spectral and physical properties. In this work, we examine 13 yr of bolometric surface temperature data from the Diviner Lunar Radiometer on board the Lunar Reconnaissance Orbiter over the ejecta blankets of 10 lunar craters of varying sizes ( D = 5–43 km) and ages (<10 to ∼200 Ma) to study the spatial variation in their thermophysical characteristics. We find that a one-dimensional thermal model with two free parameters—the bottom-layer bulk density, ρ _d , and the transition height between the surface and bottom-layer densities, H —is able to accurately fit these data over our study regions, in contrast to previous models that assumed a constant ρ _d . Based on the best-fit model parameters, young crater ejecta can be divided into three classes: (1) “blocky” regions with a high abundance of boulders >1 m in diameter, (2) “clastic” ejecta with varying levels of vertical density stratification, and (3) “impact melts” with high thermal inertia materials buried under a layer of less dense material. These thermophysically derived classes correlate strongly with observed morphology in high-resolution images and polarimetric signatures in decimeter-wavelength radar, and their thermophysical properties evolve distinctly with crater age. This technique represents the first time impact melt in many forms can be quantitatively distinguished by its physical properties from other types of ejecta using remote-sensing data and could have applications in validating models of impact ejecta production and deposition. |
| format | Article |
| id | doaj-art-a6247bcad80b4993ada64c5e85dafd3d |
| institution | OA Journals |
| issn | 2632-3338 |
| language | English |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
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| series | The Planetary Science Journal |
| spelling | doaj-art-a6247bcad80b4993ada64c5e85dafd3d2025-08-20T02:06:46ZengIOP PublishingThe Planetary Science Journal2632-33382024-01-0151126110.3847/PSJ/ad84e3Thermophysical Diversity of Young Lunar Crater Ejecta Revealed with LRO Diviner ObservationsCailin L. Gallinger0https://orcid.org/0000-0002-1465-7447Jean-Pierre Williams1https://orcid.org/0000-0003-4163-2760Catherine D. Neish2https://orcid.org/0000-0003-3254-8348Tyler M. Powell3https://orcid.org/0000-0003-3676-6561Catherine M. Elder4https://orcid.org/0000-0002-9993-8861Rebecca R. Ghent5https://orcid.org/0000-0002-3173-6630Paul O. Hayne6https://orcid.org/0000-0003-4399-0449David A. Paige7https://orcid.org/0009-0001-6122-9904Department of Earth Sciences, University of Western Ontario , 1151 Richmond Street N., London, ON N6A 5B7, Canada ; cgallin4@uwo.caDepartment of Earth, Planetary and Space Sciences, University of California, Los Angeles , 595 Charles Young Drive East, Los Angeles, CA 90095-1567, USADepartment of Earth Sciences, University of Western Ontario , 1151 Richmond Street N., London, ON N6A 5B7, Canada ; cgallin4@uwo.caApplied Physics Laboratory, Johns Hopkins University , 11100 Johns Hopkins Road, Laurel, MD 20723-60 99, USAJet Propulsion Laboratory, California Institute of Technology , 4800 Oak Grove Drive, Pasadena, CA 91109, USAPlanetary Science Institute , 1700 East Fort Lowell, Suite 106, Tucson, AZ 85719-2395, USADepartment of Astrophysical and Planetary Sciences, University of Colorado , 3665 Discovery Drive, Boulder, CO 80303, USADepartment of Earth, Planetary and Space Sciences, University of California, Los Angeles , 595 Charles Young Drive East, Los Angeles, CA 90095-1567, USAYoung (<1 Ga) craters on the Moon are known to host diverse mixtures of ejecta with varying spectral and physical properties. In this work, we examine 13 yr of bolometric surface temperature data from the Diviner Lunar Radiometer on board the Lunar Reconnaissance Orbiter over the ejecta blankets of 10 lunar craters of varying sizes ( D = 5–43 km) and ages (<10 to ∼200 Ma) to study the spatial variation in their thermophysical characteristics. We find that a one-dimensional thermal model with two free parameters—the bottom-layer bulk density, ρ _d , and the transition height between the surface and bottom-layer densities, H —is able to accurately fit these data over our study regions, in contrast to previous models that assumed a constant ρ _d . Based on the best-fit model parameters, young crater ejecta can be divided into three classes: (1) “blocky” regions with a high abundance of boulders >1 m in diameter, (2) “clastic” ejecta with varying levels of vertical density stratification, and (3) “impact melts” with high thermal inertia materials buried under a layer of less dense material. These thermophysically derived classes correlate strongly with observed morphology in high-resolution images and polarimetric signatures in decimeter-wavelength radar, and their thermophysical properties evolve distinctly with crater age. This technique represents the first time impact melt in many forms can be quantitatively distinguished by its physical properties from other types of ejecta using remote-sensing data and could have applications in validating models of impact ejecta production and deposition.https://doi.org/10.3847/PSJ/ad84e3Lunar cratersLunar surfaceLunar impactsLunar regolithRemote sensingInfrared astronomy |
| spellingShingle | Cailin L. Gallinger Jean-Pierre Williams Catherine D. Neish Tyler M. Powell Catherine M. Elder Rebecca R. Ghent Paul O. Hayne David A. Paige Thermophysical Diversity of Young Lunar Crater Ejecta Revealed with LRO Diviner Observations The Planetary Science Journal Lunar craters Lunar surface Lunar impacts Lunar regolith Remote sensing Infrared astronomy |
| title | Thermophysical Diversity of Young Lunar Crater Ejecta Revealed with LRO Diviner Observations |
| title_full | Thermophysical Diversity of Young Lunar Crater Ejecta Revealed with LRO Diviner Observations |
| title_fullStr | Thermophysical Diversity of Young Lunar Crater Ejecta Revealed with LRO Diviner Observations |
| title_full_unstemmed | Thermophysical Diversity of Young Lunar Crater Ejecta Revealed with LRO Diviner Observations |
| title_short | Thermophysical Diversity of Young Lunar Crater Ejecta Revealed with LRO Diviner Observations |
| title_sort | thermophysical diversity of young lunar crater ejecta revealed with lro diviner observations |
| topic | Lunar craters Lunar surface Lunar impacts Lunar regolith Remote sensing Infrared astronomy |
| url | https://doi.org/10.3847/PSJ/ad84e3 |
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