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

DOI: 
10.1093/mnras/stx1691
Publication date: 
01/07/2017
Main author: 
Vincent, J. -B.
IAA authors: 
Gutiérrez, P. J.;Lara, L. M.
Authors: 
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.;Barbieri, C.;Lamy, P. L.;Rodrigo, R.;Koschny, D.;A'Hearn, M. F.;Barucci, M. A.;Bertaux, J. -L.;Bertini, I.;Cremonese, G.;Da Deppo, V.;Debei, S.;De Cecco, M.;Deller, J.;Fornasier, S.;Groussin, O.;Gutiérrez, P. J.;Gutiérrez-Marquez, P.;Güttler, C.;Ip, W. -H.;Jorda, L.;Knollenberg, J.;Kovacs, G.;Kramm, J. -R.;Küppers, M.;Lara, L. M.;Lazzarin, M.;Lopez Moreno, J. J.;Marzari, F.;Naletto, G.;Penasa, L.;Shi, X.;Thomas, N.;Toth, I.;Tubiana, C.
Journal: 
Monthly Notices of the Royal Astronomical Society
Refereed: 
Yes
Publication type: 
Article
Volume: 
469
Pages: 
S329-S338
Abstract: 

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.

Database: 
ADS
SCOPUS
URL: 
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85037054854&doi=10.1093%2fmnras%2fstx1691&partnerID=40&md5=3d165de2fc4732ab5cf649f3795dd503
ADS Bibcode: 
2017MNRAS.469S.329V
Keywords: 
comets: general;comets: individual: 67P;Astrophysics - Earth and Planetary Astrophysics