1,2,2,2,1,- 1Institut für Planetologie, Universität Münster, 48149 Münster, Germany
- 2Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, RI, USA
The Rosetta mission to comet 67P/Churyumov-Gerasimenko (67P) has granted insight into the development of cometary nuclei in previously unprecedented detail. But still, the plethora of data from that mission is not fully evaluated and some driving mechanism pertaining to dust and volatile ejections [1] and surface morphology changes are not yet fully understood or only investigated for a small sample size [2, 3]. With recent tools developed to streamline and improve investigations of surface morphology changes observed during the Rosetta mission (RoSCo [4]), it is feasible to look at multiple events across the entire surface of 67P and compare their thermal environment using a thermophysical model.
MoCSI [5] is a thermophysical model designed to simulate surface and subsurface temperatures of dry-airless bodies. Since the focus of this study are geometry driven difference in received heat flux and thermal gradients in the dusty surface layer, a simple two-layer model [6] with different thermal conductivities is used and internal sublimation and gas flux is neglected. The two layers represent thermal conductivities of a mostly dry top layer and a volatile richer bottom layer.
Figure 1: Simulations of 1.5 comet rotations during 01.06.2015 and 01.08.2015 in the Khonsu region of 67P, comparable to [2]. The dashed blue line marks the time of an outburst that occurred in the region on the 01.08.2025 (outburst #7 in [7]). a) Surface temperature distribution during the outburst time and selected two facets. b) Received heat flux for both the plateau and cliff wall facet at the two dates. c) and d) Temperatures at depths of 0, 5 and 10mm for the cliff wall facet and the plateau facet respectively at both dates. e) and f) Temperature gradients between 0-1mm, 0-5mm and 5-10mm the cliff wall facet and the plateau facet respectively at both dates.
In order to compare our results to the ones of Pajola et al. [2], we also focus on two facets, one at the cliff wall of a collapsing cliff (feature F5 in [8]) and the other on top of the plateau region of that cliff. The two facets are compared at a date at which an outburst occurred in the region and another date two months prior, similar to [2]. Received heat flux, temperatures at varying depth within the first centimeter and temperature gradients are recorded and compared for multiple different cliff collapses. Figure 1 shows an example using the same depiction as [2] for a cliff collapse in the Khonsu region.
We will discuss similarities and differences between the different cliff collapse events in the different regions of 67P and what can be learned about the underlying physics that may drive these collapses.
[1] Attree, N. et al. (2025), MNRAS 541.2, pp. 771-783.
[2] Pajola, M. et al. (2017), Nature Astronomy 1, 0092.
[3] Groussin, O. et al. (2025), A&A, 694, A21.
[4] Jindal, A. S. et al. (2025), EPSC-DPS 2025, EPSC-DPS2025-838.
[5] Schuckart, C. et al. (2026), A&A, 706, A104.
[6] Jindal, A. S. et al. (2022), PSJ, 3 193.
[7] Vincent, J.B. et al. (2016), MNRAS 462(Suppl_1), pp. S184-S194.
[8] Hasselmann, P.H. et al. (2019), A&A, 630, A8.
How to cite: Schuckart, C., Jindal, A., Birch, S., Rückriemen-Bez, T., Moser, M., Fouché, E., Miller, J., Güttler, C., and Gundlach, B.: Thermophysical development of cliff collapse regions on 67P/Churyumov-Gerasimenko, Europlanet Science Congress 2026, The Hague, The Netherlands, 7–11 Sep 2026, EPSC2026-493, https://doi.org/10.5194/epsc2026-493, 2026.
