Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Catastrophic disruptions as the origin of bilobate comets

Catastrophic disruptions as the origin of bilobate comets Several comets observed at close range have bilobate shapes1, including comet 67P/Churyumov–Gerasimenko (67P/C–G), which was imaged by the European Space Agency’s Rosetta mission2,3. Bilobate comets are thought to be primordial because they are rich in supervolatiles (for example, N2 and CO) and have a low bulk density, which implies that their formation requires a very low-speed accretion of two bodies. However, slow accretion does not only occur during the primordial phase of the Solar System; it can also occur at later epochs as part of the reaccumulation process resulting from the collisional disruption of a larger body4, so this cannot directly constrain the age of bilobate comets. Here, we show by numerical simulation that 67P/C–G and other elongated or bilobate comets can be formed in the wake of catastrophic collisional disruptions of larger bodies while maintaining their volatiles and low density throughout the process. Since this process can occur at any epoch of our Solar System’s history, from early on through to the present day5, there is no need for these objects to be formed primordially. These findings indicate that observed prominent geological features, such as pits and stratified surface layers4,5, may not be primordial. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Nature Astronomy Springer Journals

Catastrophic disruptions as the origin of bilobate comets

Loading next page...
 
/lp/springer-journals/catastrophic-disruptions-as-the-origin-of-bilobate-comets-RY9PqMfYxq

References (43)

Publisher
Springer Journals
Copyright
Copyright © The Author(s) 2018
Subject
Physics; Physics, general; Astronomy, Astrophysics and Cosmology
eISSN
2397-3366
DOI
10.1038/s41550-018-0395-2
Publisher site
See Article on Publisher Site

Abstract

Several comets observed at close range have bilobate shapes1, including comet 67P/Churyumov–Gerasimenko (67P/C–G), which was imaged by the European Space Agency’s Rosetta mission2,3. Bilobate comets are thought to be primordial because they are rich in supervolatiles (for example, N2 and CO) and have a low bulk density, which implies that their formation requires a very low-speed accretion of two bodies. However, slow accretion does not only occur during the primordial phase of the Solar System; it can also occur at later epochs as part of the reaccumulation process resulting from the collisional disruption of a larger body4, so this cannot directly constrain the age of bilobate comets. Here, we show by numerical simulation that 67P/C–G and other elongated or bilobate comets can be formed in the wake of catastrophic collisional disruptions of larger bodies while maintaining their volatiles and low density throughout the process. Since this process can occur at any epoch of our Solar System’s history, from early on through to the present day5, there is no need for these objects to be formed primordially. These findings indicate that observed prominent geological features, such as pits and stratified surface layers4,5, may not be primordial.

Journal

Nature AstronomySpringer Journals

Published: May 1, 2018

There are no references for this article.