Constraints on cometary surface evolution derived from a statistical analysis of 67P’s topography

Vincent, J.-B.; Hviid, S. F.; Mottola, S.; Kuehrt, E.; Preusker, F.; Scholten, F.; Keller, H. U.; Oklay, N.; de Niem, D.; Davidsson, B.; Fulle, M.; Pajola, M.; Hofmann, M.; Hu, X.; Rickman, H.; Lin, Z.-Y.; Feller, C.; Gicquel, A.; Boudreault, S.; Sierks, H.; ... (2017). Constraints on cometary surface evolution derived from a statistical analysis of 67P’s topography. Monthly notices of the Royal Astronomical Society, 469(Suppl_2), S329-S338. Oxford University Press 10.1093/mnras/stx1691

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We present a statistical analysis of the distribution of large-scale topographic features on comet 67P/Churyumov–Gerasimenko.We observe that the cumulative cliff height distribution across the surface follows a power law with a slope equal to −1.69 ± 0.02. When this distribution is studied independently for each region, we find a good correlation between the slope of the power law and the orbital erosion rate of the surface. For instance, the Northern hemisphere topography is dominated by structures on the 100 m scale, while the Southern hemisphere topography, illuminated at perihelion, is dominated by 10 m scale terrain features. Our study suggests that the current size of a cliff is controlled not only by material cohesion but also by the dominant erosional process in each region. This observation can be generalized to other comets, where we argue that primitive nuclei are characterized by the presence of large cliffs with a cumulative height-power index equal to or above −1.5, while older, eroded cometary surfaces have a power index equal to or below −2.3. In effect, our model shows that a measure of the topography provides a quantitative assessment of a comet’s erosional history, that is, its evolutionary age.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Physics Institute > Space Research and Planetary Sciences

UniBE Contributor:

Thomas, Nicolas

Subjects:

500 Science > 520 Astronomy
600 Technology > 620 Engineering

ISSN:

0035-8711

Publisher:

Oxford University Press

Language:

English

Submitter:

Dora Ursula Zimmerer

Date Deposited:

20 Nov 2017 10:48

Last Modified:

20 Nov 2017 10:48

Publisher DOI:

10.1093/mnras/stx1691

BORIS DOI:

10.7892/boris.105860

URI:

https://boris.unibe.ch/id/eprint/105860

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