{"title":"Low Rock Mass Fraction Within Trans-Neptunian Objects Inferred From the Spin–Orbit Evolution of Orcus–Vanth and Salacia–Actaea","authors":"S. Arakawa, S. Kamata, H. Genda","doi":"10.1029/2024JE008923","DOIUrl":null,"url":null,"abstract":"<p>Satellites play a crucial role in understanding the formation and evolution of trans-Neptunian objects (TNOs). The spin–orbit evolution of satellite systems depends on their thermal histories, allowing us to constrain the rock mass fraction within TNOs based on their current spin–orbit states. In this study, we perform coupled thermal–orbital evolution calculations for two satellite systems around undifferentiated TNOs: Orcus–Vanth and Salacia–Actaea. Our results demonstrate that the current spin–orbit states of these systems are consistent with a rock mass fraction of approximately 20%–30%. Additionally, we estimate the organic mass fraction within the TNOs and find that it is comparable to the rock mass fraction. These findings suggest that the chemical composition of TNOs closely resembles that of comets.</p>","PeriodicalId":16101,"journal":{"name":"Journal of Geophysical Research: Planets","volume":"130 4","pages":""},"PeriodicalIF":4.0000,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Geophysical Research: Planets","FirstCategoryId":"89","ListUrlMain":"https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024JE008923","RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
Satellites play a crucial role in understanding the formation and evolution of trans-Neptunian objects (TNOs). The spin–orbit evolution of satellite systems depends on their thermal histories, allowing us to constrain the rock mass fraction within TNOs based on their current spin–orbit states. In this study, we perform coupled thermal–orbital evolution calculations for two satellite systems around undifferentiated TNOs: Orcus–Vanth and Salacia–Actaea. Our results demonstrate that the current spin–orbit states of these systems are consistent with a rock mass fraction of approximately 20%–30%. Additionally, we estimate the organic mass fraction within the TNOs and find that it is comparable to the rock mass fraction. These findings suggest that the chemical composition of TNOs closely resembles that of comets.
期刊介绍:
The Journal of Geophysical Research Planets is dedicated to the publication of new and original research in the broad field of planetary science. Manuscripts concerning planetary geology, geophysics, geochemistry, atmospheres, and dynamics are appropriate for the journal when they increase knowledge about the processes that affect Solar System objects. Manuscripts concerning other planetary systems, exoplanets or Earth are welcome when presented in a comparative planetology perspective. Studies in the field of astrobiology will be considered when they have immediate consequences for the interpretation of planetary data. JGR: Planets does not publish manuscripts that deal with future missions and instrumentation, nor those that are primarily of an engineering interest. Instrument, calibration or data processing papers may be appropriate for the journal, but only when accompanied by scientific analysis and interpretation that increases understanding of the studied object. A manuscript that describes a new method or technique would be acceptable for JGR: Planets if it contained new and relevant scientific results obtained using the method. Review articles are generally not appropriate for JGR: Planets, but they may be considered if they form an integral part of a special issue.