Search Publications
On deviations from free-radial outflow in the inner coma of comet 67P/Churyumov-Gerasimenko
Jorda, L.; Lamy, P. L.; Lara, L. M. +44 more
The Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) onboard the European Space Agency's Rosetta spacecraft acquired images of comet 67P/Churyumov-Gerasimenko (67P) and its surrounding dust coma starting from May 2014 until September 2016. In this paper we present methods and results from analysis of OSIRIS images regarding the …
Meter-scale thermal contraction crack polygons on the nucleus of comet 67P/Churyumov-Gerasimenko
Jorda, L.; Lamy, P. L.; Lara, L. M. +48 more
We report on the detection and characterization of more than 6300 polygons on the surface of the nucleus of comet 67P/Churyumov-Gerasimenko, using images acquired by the OSIRIS camera onboard Rosetta between August 2014 and March 2015. They are found in consolidated terrains and grouped in localized networks. They are present at all latitudes (fro…
Structure and elastic parameters of the near surface of Abydos site on comet 67P/Churyumov-Gerasimenko, as obtained by SESAME/CASSE listening to the MUPUS insertion phase
Knollenberg, J.; Knapmeyer, M.; Fischer, H. -H. +5 more
The accelerometers of the SESAME/CASSE instrument aboard Rosetta's lander Philae recorded surface waves produced during the MUPUS hammering phase. After presenting evidence that all feet of Philae were in contact with the ground, we analyze group arrival time differences between the three feet of Philae and obtain a Rayleigh wave velocity between …
Laboratory simulations of the Vis-NIR spectra of comet 67P using sub-µm sized cosmochemical analogues
Kappel, D.; Bockelée-Morvan, D.; Capaccioni, F. +16 more
Laboratory spectral measurements of relevant analogue materials were performed in the framework of the Rosetta mission in order to explain the surface spectral properties of comet 67P. Fine powders of coal, iron sulphides, silicates and their mixtures were prepared and their spectra measured in the Vis-IR range. These spectra are compared to a ref…
Ultraviolet spectral reflectance of carbonaceous materials
Gillis-Davis, Jeffrey J.; Hendrix, Amanda R.; Roush, Ted L. +5 more
A number of planetary spacecraft missions have carried instruments with sensors covering the ultraviolet (UV) wavelength range. However, there exists a general lack of relevant UV reflectance laboratory data to compare against these planetary surface remote sensing observations in order to make confident material identifications. To address this n…
Comet 67p/Churyumov-Gerasimenko, possible origin of the depression Hatmehit
Czechowski, Leszek; Kossacki, Konrad J.
On the nucleus of comet 67P/Churyumov-Gerasimenko numerous pits and depressions of different sizes are identified. In the present work the origin of depression Hatmehit is investigated. We propose a mechanism that includes recession of the surface due to sub-dust sublimation together with formation of cavities. Recession of the surface is calculat…
Constraining the parameter space of comet simulation experiments
Hagermann, Axel; Kaufmann, Erika
Our interpretation of the data returned by Rosetta and other cometary missions is based on the predictions of theoretical models and the results of laboratory experiments. For example, Kossacki et al. (2015) showed that 67P's surface hardness reported by Spohn et al. (2015) can be explained by sintering. The present work supports Rosetta's observa…
Compressive strength and elastic modulus at Agilkia on comet 67P/Churyumov-Gerasimenko derived from the SESAME/CASSE touchdown signals
Flandes, Alberto; Krüger, Harald; Arnold, Walter +8 more
We report an analysis of the Comet Acoustic Surface Sounding Experiment (CASSE) acceleration signals at Philae's first touchdown site Agilkia on comet 67P/Churyumov-Gerasimenko. The signals yield the forces in the contact zone foot-sole and comet surface, and from these forces a compression strength of approximately 10 kPa can be derived. The sole…
Evolution of H2O production in comet C/2012 S1 (ISON) as inferred from forbidden oxygen and OH emission
Harris, Walter M.; Cochran, Anita L.; Weaver, Harold +5 more
We present H2O production rates for comet C/2012 S1 (ISON) derived from observations of [O I] and OH emission during its inbound leg, covering a heliocentric distance range of 1.8-0.44 AU. Our production rates are in agreement with previous measurements using a variety of instruments and techniques and with data from the various observa…
On the origin of internal layers in comet nuclei
Li, Jian-Yang; Belton, Michael J. S.; Asphaug, Erik +1 more
We present an analysis of the layered structure on 67P/Churyumov-Gerasimenko' s Hathor cliff and propose a mechanism (self-sustaining, dual-mode propagation of amorphous to crystalline ice phase-change fronts into the nucleus interior) for its origin. If this is a viable mechanism, the strata must be geologically young (∼106 y). The Hat…