CO<SUB>2</SUB>-driven surface changes in the Hapi region on Comet 67P/Churyumov-Gerasimenko - Archive ouverte HAL Access content directly
Journal Articles Monthly Notices of the Royal Astronomical Society Year : 2022

CO2-driven surface changes in the Hapi region on Comet 67P/Churyumov-Gerasimenko

, , (1, 2) , , , , , , , , , , , , , , (1) , , , (3) , , , , , , ,
1
2
3
Björn J. R. Davidsson
  • Function : Author
F. Peter Schloerb
  • Function : Author
Nilda Oklay
  • Function : Author
Pedro J. Gutiérrez
  • Function : Author
Bonnie J. Buratti
  • Function : Author
Artur B. Chmielewski
  • Function : Author
Samuel Gulkis
  • Function : Author
Mark D. Hofstadter
  • Function : Author
H. Uwe Keller
  • Function : Author
Holger Sierks
  • Function : Author
Carsten Güttler
  • Function : Author
Michael Küppers
  • Function : Author
Hans Rickman
  • Function : Author
Mathieu Choukroun
  • Function : Author
Seungwon Lee
  • Function : Author
Anthony Lethuillier
  • Function : Author
Vania da Deppo
  • Function : Author
Ekkehard Kührt
  • Function : Author
Nicolas Thomas
  • Function : Author
Cecilia Tubiana
  • Function : Author
M. Ramy El-Maarry
  • Function : Author
Fiorangela La Forgia
  • Function : Author
Stefano Mottola
  • Function : Author
Maurizio Pajola
  • Function : Author

Abstract

Between 2014 December 31 and 2015 March 17, the OSIRIS cameras on Rosetta documented the growth of a 140 m wide and 0.5 m deep depression in the Hapi region on Comet 67P/Churyumov-Gerasimenko. This shallow pit is one of several that later formed elsewhere on the comet, all in smooth terrain that primarily is the result of airfall of coma particles. We have compiled observations of this region in Hapi by the microwave instrument MIRO on Rosetta, acquired during October and November 2014. We use thermophysical and radiative transfer models in order to reproduce the MIRO observations. This allows us to place constraints on the thermal inertia, diffusivity, chemical composition, stratification, extinction coefficients, and scattering properties of the surface material, and how they evolved during the months prior to pit formation. The results are placed in context through long-term comet nucleus evolution modelling. We propose that: 1) MIRO observes signatures that are consistent with a solid-state greenhouse effect in airfall material; 2) CO2 ice is sufficiently close to the surface to have a measurable effect on MIRO antenna temperatures, and likely is responsible for the pit formation in Hapi observed by OSIRIS; 3) the pressure at the CO2 sublimation front is sufficiently strong to expel dust and water ice outwards, and to compress comet material inwards, thereby causing the near-surface compaction observed by CONSERT, SESAME, and groundbased radar, manifested as the 'consolidated terrain' texture observed by OSIRIS.

Dates and versions

insu-03780742 , version 1 (19-09-2022)

Identifiers

Cite

Björn J. R. Davidsson, F. Peter Schloerb, Sonia Fornasier, Nilda Oklay, Pedro J. Gutiérrez, et al.. CO2-driven surface changes in the Hapi region on Comet 67P/Churyumov-Gerasimenko. Monthly Notices of the Royal Astronomical Society, 2022, ⟨10.1093/mnras/stac2560⟩. ⟨insu-03780742⟩
9 View
0 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More