The Effects of Early Collisional Evolution on Amorphous Water Ice Bodies
Conditions in the outer protoplanetary disk during solar system formation were thought to be favorable for the formation of amorphous water ice (AWI), a glassy phase of water ice. However, subsequent collisional processing could have shock-crystallized any AWI present. Here we use the iSALE shock ph...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Planetary Science Journal |
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| Online Access: | https://doi.org/10.3847/PSJ/aca75a |
| _version_ | 1797368162100969472 |
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| author | Jordan K. Steckloff Gal Sarid Brandon C. Johnson |
| author_facet | Jordan K. Steckloff Gal Sarid Brandon C. Johnson |
| author_sort | Jordan K. Steckloff |
| collection | DOAJ |
| description | Conditions in the outer protoplanetary disk during solar system formation were thought to be favorable for the formation of amorphous water ice (AWI), a glassy phase of water ice. However, subsequent collisional processing could have shock-crystallized any AWI present. Here we use the iSALE shock physics hydrocode to simulate impacts between large icy bodies at impact velocities relevant to these collisional environments, and then we feed these results into a custom-built AWI crystallization script, to compute how much AWI crystallizes/survives these impact events. We find that impact speeds between icy bodies after planet migration (i.e., between trans-Neptunian objects) are too slow to crystallize any meaningful fraction of AWI. During planet migration, however, the amount of AWI that crystallizes is highly stochastic: relatively little AWI crystallizes at lower impact velocities (less than ∼2 km s ^−1 ), yet most AWI present in the bodies (if equally sized) or impactor and impact site (if different sizes) crystallizes at higher impact velocities (greater than ∼4 km s ^−1 ). Given that suspected impact speeds during planet migration were ∼2–4 km s ^−1 , this suggests that primordial AWI’s ability to survive planet migration is highly stochastic. However, if proto-Edgeworth–Kuiper Belt (proto-EKB) objects and their fragments experienced multiple impact events, nearly all primordial AWI could have crystallized; such a highly collisional proto-EKB during planet migration is consistent with the lack of any unambiguous direct detection of AWI on any icy body. Ultimately, primordial AWI’s survival to the present day depends sensitively on the proto-EKB’s size–frequency distribution, which is currently poorly understood. |
| first_indexed | 2024-03-08T17:28:42Z |
| format | Article |
| id | doaj.art-63f5254ddb284ee29845138218c9d8b8 |
| institution | Directory Open Access Journal |
| issn | 2632-3338 |
| language | English |
| last_indexed | 2024-03-08T17:28:42Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Planetary Science Journal |
| spelling | doaj.art-63f5254ddb284ee29845138218c9d8b82024-01-02T17:21:41ZengIOP PublishingThe Planetary Science Journal2632-33382023-01-0141410.3847/PSJ/aca75aThe Effects of Early Collisional Evolution on Amorphous Water Ice BodiesJordan K. Steckloff0https://orcid.org/0000-0002-1717-2226Gal Sarid1https://orcid.org/0000-0001-5678-5044Brandon C. Johnson2https://orcid.org/0000-0002-4267-093XPlanetary Science Institute , 1700 East Fort Lowell, Suite 106, Tucson, AZ 85719, USA ; jordan@psi.edu; Department of Aerospace Engineering and Engineering Mechanics, University of Texas at Austin , 2617 Wichita Street, C0600, Austin, TX 78712, USASETI Institute , 339 Bernardo Avenue, Suite 200, Mountain View, CA 94043, USADepartment of Earth, Atmospheric, and Planetary Sciences, Purdue University , 550 Stadium Mall Drive, West Lafayette, IN 47907, USA; Department of Physics and Astronomy, Purdue University , 525 Northwestern Avenue, West Lafayette, IN 47907, USAConditions in the outer protoplanetary disk during solar system formation were thought to be favorable for the formation of amorphous water ice (AWI), a glassy phase of water ice. However, subsequent collisional processing could have shock-crystallized any AWI present. Here we use the iSALE shock physics hydrocode to simulate impacts between large icy bodies at impact velocities relevant to these collisional environments, and then we feed these results into a custom-built AWI crystallization script, to compute how much AWI crystallizes/survives these impact events. We find that impact speeds between icy bodies after planet migration (i.e., between trans-Neptunian objects) are too slow to crystallize any meaningful fraction of AWI. During planet migration, however, the amount of AWI that crystallizes is highly stochastic: relatively little AWI crystallizes at lower impact velocities (less than ∼2 km s ^−1 ), yet most AWI present in the bodies (if equally sized) or impactor and impact site (if different sizes) crystallizes at higher impact velocities (greater than ∼4 km s ^−1 ). Given that suspected impact speeds during planet migration were ∼2–4 km s ^−1 , this suggests that primordial AWI’s ability to survive planet migration is highly stochastic. However, if proto-Edgeworth–Kuiper Belt (proto-EKB) objects and their fragments experienced multiple impact events, nearly all primordial AWI could have crystallized; such a highly collisional proto-EKB during planet migration is consistent with the lack of any unambiguous direct detection of AWI on any icy body. Ultimately, primordial AWI’s survival to the present day depends sensitively on the proto-EKB’s size–frequency distribution, which is currently poorly understood.https://doi.org/10.3847/PSJ/aca75aComet volatilesSolar system formationImpact phenomenaKuiper belt |
| spellingShingle | Jordan K. Steckloff Gal Sarid Brandon C. Johnson The Effects of Early Collisional Evolution on Amorphous Water Ice Bodies The Planetary Science Journal Comet volatiles Solar system formation Impact phenomena Kuiper belt |
| title | The Effects of Early Collisional Evolution on Amorphous Water Ice Bodies |
| title_full | The Effects of Early Collisional Evolution on Amorphous Water Ice Bodies |
| title_fullStr | The Effects of Early Collisional Evolution on Amorphous Water Ice Bodies |
| title_full_unstemmed | The Effects of Early Collisional Evolution on Amorphous Water Ice Bodies |
| title_short | The Effects of Early Collisional Evolution on Amorphous Water Ice Bodies |
| title_sort | effects of early collisional evolution on amorphous water ice bodies |
| topic | Comet volatiles Solar system formation Impact phenomena Kuiper belt |
| url | https://doi.org/10.3847/PSJ/aca75a |
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