Geomorphology Of Comet 67P/Churyumov-Gerasimenko

Keywords

comets: general; comets: individual: 67P/Churyumov-Gerasimenko

Abstract

We present a global geomorphological map of comet 67P/Churyumov-Gerasimenko (67P/C-G) using data acquired by the Rosetta Orbiter's OSIRIS Narrow Angle Camera. The images used in our study were acquired between 2014 August and 2015 May, before 67P/C-G passed through perihelion. Imagery of the Southern hemisphere was included in our study, allowing us to compare the contrasting hemispheres of 67P/C-G in a single study. Our work also puts into greater context the morphologies studied in previous works, and also the morphologies observed on previously visited cometary nuclei. Relative to other nuclei, 67P/C-G appears most similar to 81P/Wild 2, with a topographically heterogeneous surface dominated by smooth-floored pits. Our mapping describes the landscapes of 67P/C-G when they were first observed by Rosetta, and our map can be used to detect changes in surface morphologies after its perihelion passage. Our mapping reveals strong latitudinal dependences for emplaced units and a highly heterogeneous surface. Layered bedrock units that represent the exposed nucleus of 67P/C-G are dominant at southern latitudes, while topographically smooth, dust covered regions dominate the Northern hemisphere. Equatorial latitudes are dominated by smooth terrain units that show evidence for flow structures. We observe no obvious differences between the comet's two lobes, with the only longitudinal variations being the Imhotep and Hatmehit basins. These correlations suggest a strong seasonal forcing on the surface evolution of 67P/C-G, where materials are transported from the Southern hemisphere to Northern hemisphere basins over multiple orbital time-scales.

Publication Date

7-1-2017

Publication Title

Monthly Notices of the Royal Astronomical Society

Volume

469

Number of Pages

S50-S67

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1093/mnras/stx1096

Socpus ID

85056332537 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/85056332537

This document is currently not available here.

Share

COinS