@article{1f465931df854af588ba281b6300b8ba,
title = "The Agilkia boulders/pebbles size-frequency distributions: OSIRIS and ROLIS joint observations of 67P surface",
abstract = "By using the images acquired by the OSIRIS (Optical, Spectroscopic and Infrared Remote Imaging System) and ROLIS (ROsetta Lander Imaging System) cameras, we derive the size- frequency distribution (SFD) of cometary pebbles and boulders covering the size range 0.05- 30.0 m on the Agilkia landing site. The global SFD measured on OSIRIS images, reflects the different properties of the multiple morphological units present on Agilkia, combined with selection effects related to lifting, transport and redeposition. Contrarily, the different ROLIS SFD derived on the smooth and rough units may be related to their different regolith thickness present on Agilkia. In the thicker, smoother layer, ROLIS mainly measures the SFD of the airfall population which almost completely obliterates the signature of underlying boulders up to a size of the order of 1 m. This is well matched by the power-law index derived analysing coma particles identified by the grain analyser Grain Impact Analyser and Dust Accumulator. This result confirms the important blanketing dynamism of Agilkia. The steeper SFD observed in rough terrains from 0.4 to 2 m could point out intrinsic differences between northern and southern dust size distributions, or it may suggest that the underlying boulders 'peek through' the thinner airfall layer in the rough terrain, thereby producing the observed excess in the decimetre size range. Eventually, the OSIRIS SFD performed on the Philae landing unit may be due to water sublimation from a static population of boulders, affecting smaller boulders before the bigger ones, thus shallowing the original SFD.",
keywords = "67P C-G, data analysis-methods, Individual, Methods, Statistical-comets",
author = "M. Pajola and S. Mottola and M. Hamm and M. Fulle and B. Davidsson and C. Guttler and H. Sierks and G. Naletto and G. Arnold and Grothues, \{H. G.\} and R. Jaumann and H. Michaelis and Bibring, \{J. P.\} and C. Barbieri and Lamy, \{P. L.\} and R. Rodrigo and D. Koschny and H. Rickman and Keller, \{H. U.\} and J. Agarwal and A'Hearn, \{M. F.\} and Barucci, \{M. A.\} and Bertaux, \{J. L.\} and I. Bertini and S. Boudreault and G. Cremonese and \{Da Deppo\}, V. and S. Debei and \{De Cecco\}, M. and J. Deller and \{El Maarry\}, \{M. R.\} and C. Feller and S. Fornasier and A. Gicquel and O. Groussin and Gutierrez, \{P. J.\} and M. Hofmann and Hviid, \{S. F.\} and Ip, \{W. H.\} and L. Jorda and J. Knollenberg and Kramm, \{J. R.\} and E. Kuhrt and M. Kuppers and \{La Forgia\}, F. and Lara, \{L. M.\} and Lin, \{Z. Y.\} and M. Lazzarin and \{Lopez Moreno\}, \{J. J.\} and A. Lucchetti and F. Marzari and M. Massironi and H. Michalik and N. Oklay and A. Pommerol and F. Preusker and F. Scholten and N. Thomas and C. Tubiana and Vincent, \{J. B.\}",
note = "Funding Information: OSIRIS was built by a consortium of the Max-Planck-Institut f?r Sonnensystemforschung, in G?ttingen, Germany, CISASUniversity of Padova, Italy, the Laboratoire d'Astrophysique de Marseille, France, the Instituto de Astrofisica de Andalucia, CSIC, Granada, Spain, the Research and Scientific Support Department of the European Space Agency, Noordwijk, the Netherlands, the Instituto Nacional de Tecnica Aeroespacial, Madrid, Spain, the Universidad Politechnica de Madrid, Spain, the Department of Physics and Astronomy of Uppsala University, Sweden, and the Institut f?r Datentechnik und Kommunikationsnetze der Technischen Universit ?t Braunschweig, Germany. The support of the national funding agencies of Germany (Deutsches Zentrum f?r Luft-und Raumfahrt), Italy (Agenzia Spaziale Italiana), France (Centre National d'Etudes Spatiales), Spain (Ministerio de Educaci?n y Ciencia), Sweden (Swedish National Space Board) and the European Space Agency (ESA) Technical Directorate is gratefully acknowledged. We thank the ESA teams at European Space Astronomy Center, European Space Operation Center and European Space Research and Technology Center for their work in support of the Rosetta mission. ROLIS was funded, built and managed by the DLR, German Aerospace Center, which we gratefully acknowledge. The ROLIS Team is indebted to the Lander Control Center (LCC, Cologne), CNES's Science, Operation, and Navigation Center (SONC) and the European Space Agency (ESA) for their support during the operations. We thank W. Bresch for his continued support during the development and operations of the experiment. MP was supported for this research in part by an appointment to the National Aeronautics and Space Administration (NASA) Postdoctoral Program at the Ames Research Center administered by Universities Space Research Association (USRA) through a contract with NASA. We made use of the ARCGIS 10.2 software together with IDL, MATLAB and R software to perform the presented analysis.",
year = "2016",
doi = "10.1093/mnras/stw2720",
language = "British English",
volume = "462",
pages = "S242--S252",
journal = "Monthly Notices of the Royal Astronomical Society",
issn = "0035-8711",
publisher = "Oxford University Press",
}