Comparison of central pit craters on Mars, Mercury, Ganymede, and the Saturnian satellites
| Autor: | Nadine G. Barlow, Aviva Maine, Ryan M. Horstman, Sierra Ferguson |
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| Rok vydání: | 2017 |
| Předmět: |
Martian
Solar System geography geography.geographical_feature_category 010504 meteorology & atmospheric sciences Bedrock Earth science Geochemistry chemistry.chemical_element Crust Mars Exploration Program Surface gravity 01 natural sciences Mercury (element) Geophysics chemistry Impact crater Space and Planetary Science 0103 physical sciences 010303 astronomy & astrophysics Geology 0105 earth and related environmental sciences |
| Zdroj: | Meteoritics & Planetary Science. 52:1371-1387 |
| ISSN: | 1086-9379 |
| Popis: | We report on the first results of a large-scale comparison study of central pit craters throughout the solar system, focused on Mars, Mercury, Ganymede, Rhea, Dione, and Tethys. We have identified 10 more central pit craters on Rhea, Dione, and Tethys than have previously been reported. We see a general trend that the median ratio of the pit to crater diameter (Dp/Dc) decreases with increasing gravity and decreasing volatile content of the crust. Floor pits are more common on volatile-rich bodies while summit pits become more common as crustal volatile content decreases. Uplifted bedrock from below the crater floor occurs in the central peak upon which summit pits are found and in rims around floor pits, which may or may not break the surface. Peaks on which summit pits are found on Mars and Mercury share similar characteristics to those of nonpitted central peaks, indicating that some normal central peaks undergo an additional process to create summit pits. Martian floor pits do not appear to be the result of a central peak collapse as the median ratio of the peak to crater diameter (Dpk/Dc) is about twice as high for central peaks/summit pits than Dp/Dc values for floor pits. Median Dpk/Dc is twice as high for Mars as for Mercury, reflecting differing crustal strength between the two bodies. Results indicate that a complicated interplay of crustal volatiles, target strength, surface gravity, and impactor energy along with both uplift and collapse are involved in central pit formation. Multiple formation models may be required to explain the range of central pits seen throughout the solar system. |
| Databáze: | OpenAIRE |
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