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491 results on '"Kührt, E."'

1. Modeling of the outburst on July 29th, 2015 observed with OSIRIS cameras in the southern hemisphere of comet 67P/Churyumov-Gerasimenko

Author

Gicquel, A., Rose, M., Vincent, J. -B., Davidsson, B., Bodewits, D., Hearn, M. F. A, Agarwal, J., Fougere, N., Sierks, H., Bertini, I., Lin, Z. -Y., Barbieri, C., Lamy, P. L., Rodrigo, R., Koschny, D., Rickman, H., Keller, H. U., Barucci, M. A., Bertaux, J. -L., Besse, S., Boudreault, S., Cremonese, G., Da Deppo, V., Debei, S., Deller, J., De Cecco, M., Frattin, E., El-Maarry, M. R., Fornasier, S., Fulle, M., Groussin, O., Gutierrez, P. J., Gutierrez-Marquez, P., Guttler, C., Hofner, S., Hofmann, M., Hu, X., Hviid, S. F., Ip, W. -H., Jorda, L., Knollenberg, J., Kovacs, G., Kramm, J. -R., Kuhrt, E., Kuppers, M., Lara, L. M., Lazzarin, M., Moreno, J. J. Lopez, Lowry, S., Marzari, F., Masoumzadeh, N., Massironi, M., Moreno, F., Mottola, S., Naletto, G., Oklay, N., Pajola, M., Preusker, F., Scholten, F., Shi, X., Thomas, N., Toth, I., and Tubiana, C.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

Images of the nucleus and the coma (gas and dust) of comet 67P/Churyumov- Gerasimenko have been acquired by the OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System) cameras since March 2014 using both the Wide Angle Camera (WAC) and the Narrow Angle Camera (NAC). We use images from the NAC camera to study a bright outburst observed in the southern hemisphere on July 29, 2015. The high spatial resolution of the NAC is needed to localize the source point of the outburst on the surface of the nucleus. The heliocentric distance is 1.25 au and the spacecraft-comet distance is 186 km. Aiming to better understand the physics that led to the outgassing, we used the Direct Simulation Monte Carlo (DSMC) method to study the gas flow close to the nucleus and the dust trajectories. The goal is to understand the mechanisms producing the outburst. We reproduce the opening angle of the outburst in the model and constrain the outgassing ratio between the outburst source and the local region. The outburst is in fact a combination of both gas and dust, in which the active surface is approximately 10 times more active than the average rate found in the surrounding areas. We need a number of dust particles 7.83 $\times$ 10$^{11}$ - 6.90 $\times$ 10$^{15}$ (radius 1.97 - 185 {\mu}m), which corresponds to a mass of dust 220 - 21 $\times$ 10$^{3}$kg., Comment: 8 pages, 9 figures

Published
2017
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3. Observations and analysis of a curved jet in the coma of comet 67P/Churyumov-Gerasimenko

Author

Lin, Zhong-Yi, Lai, I. -L., Su, C. -C., Ip, W. -H., Lee, J. -C., Wu, J. -S., Vincent, J. -B., La Forgia, F., Sierks, H., Barbieri, C., Lamy, P. L., Rodrigo, R., Koschny, D., Rickman, H., Keller, H. U., Agarwal, J., A'Hearn, M. F., Barucci, M. A., Bertaux, J. -L., Bertini, I., Bodewits, D., Cremonese, G., Da Deppo, V., Davidsson, B., Debet, S., De Cecco, M., Fornasier, S., Fulle, M., Groussin, O., Gutierrez, P. J., Guttler, C., Hviid, S. F., Jorda, L., Knollenberg, J., Kovacs, G., Kramm, J. -R., Kuhrt, E., Kuppers, M., Lara, L. M., Lazzarin, M., Lopez-Moreno, J. J., Lowry, S., Marzari, F., Michalik, H., Mottola, S., Naletto, G., Oklay, N., Pajola, M., Rozek, A., Thomas, N., and Tubiana, C.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

We analyze the physical properties and dynamical origin of a curved jet of comet 67P/Churyumov-Gerasimenko that was observed repeatedly in several nucleus rotations starting on May 30 and persisting until early August, 2015. We simulated the motion of dust grains ejected from the nucleus surface under the influence of the gravity and viscous drag effect of the expanding gas flow from the rotating nucleus. The formation of the curved jet is a combination of the size of the dust particles (~0.1-1 mm) and the location of the source region near the nucleus equator. This enhances the spiral feature of the collimated dust stream after the dust is accelerated to a terminal speed on the order of m/s., Comment: 5pages, 5 figures

Published
2016
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4. A nanolander for a space mission to an active asteroid in the main belt

Author

Ho, T.M., primary, Kührt, E., additional, Zhang, X.J., additional, Auster, U., additional, Biele, J., additional, Grott, M., additional, Grundmann, J.T., additional, He, H., additional, Hördt, A., additional, Huang, J.C., additional, Ma, T., additional, Mottola, S., additional, Otto, K., additional, Plettemeier, D., additional, Qin, L., additional, Rubin, M., additional, Schmitz, N., additional, Ulamec, S., additional, and Vincent, J.B., additional

Published
2023
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5. Low thermal conductivity boulder with high porosity identified on C-type asteroid (162173) Ryugu

Author

Grott, M., Knollenberg, J., Hamm, M., Ogawa, K., Jaumann, R., Otto, K. A., Delbo, M., Michel, P., Biele, J., Neumann, W., Knapmeyer, M., Kührt, E., Senshu, H., Okada, T., Helbert, J., Maturilli, A., Müller, N., Hagermann, A., Sakatani, N., Tanaka, S., Arai, T., Mottola, S., Tachibana, S., Pelivan, I., Drube, L., Vincent, J.-B., Yano, H., Pilorget, C., Matz, K. D., Schmitz, N., Koncz, A., Schröder, S. E., Trauthan, F., Schlotterer, M., Krause, C., Ho, T.-M., and Moussi-Soffys, A.

Published
2019
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6. The changing temperature of the nucleus of comet 67P induced by morphological and seasonal effects

Author

Tosi, F., Capaccioni, F., Capria, M. T., Mottola, S., Zinzi, A., Ciarniello, M., Filacchione, G., Hofstadter, M., Fonti, S., Formisano, M., Kappel, D., Kührt, E., Leyrat, C., Vincent, J.-B., Arnold, G., De Sanctis, M. C., Longobardo, A., Palomba, E., Raponi, A., Rousseau, B., Schmitt, B., Barucci, M. A., Bellucci, G., Benkhoff, J., Bockelée-Morvan, D., Cerroni, P., Combe, J.-Ph., Despan, D., Erard, S., Mancarella, F., McCord, T. B., Migliorini, A., Orofino, V., and Piccioni, G.

Published
2019
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7. Coma morphology of comet 67P controlled by insolation over irregular nucleus

Author

Shi, X., Hu, X., Mottola, S., Sierks, H., Keller, H. U., Rose, M., Güttler, C., Fulle, M., Fornasier, S., Agarwal, J., Pajola, M., Tubiana, C., Bodewits, D., Barbieri, C., Lamy, P. L., Rodrigo, R., Koschny, D., Barucci, M. A., Bertaux, J.-L., Bertini, I., Boudreault, S., Cremonese, G., Da Deppo, V., Davidsson, B., Debei, S., De Cecco, M., Deller, J., Groussin, O., Gutiérrez, P. J., Hviid, S. F., Ip, W.-H., Jorda, L., Knollenberg, J., Kovacs, G., Kramm, J.-R., Kührt, E., Küppers, M., Lara, L. M., Lazzarin, M., Lopez-Moreno, J. J., Marzari, F., Naletto, G., Oklay, N., Toth, I., and Vincent, J.-B.

Published
2018
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12. THERMAP: a mid-infrared spectro-imager for space missions to small bodies in the inner solar system

Author

Groussin, O., Licandro, J., Helbert, J., Reynaud, J. L., Levacher, P., Reyes García-Talavera, M., Alí-Lagoa, V., Blanc, P. E., Brageot, E., Davidsson, B., Delbó, M., Deleuze, M., Delsanti, A., Diaz Garcia, J. J., Dohlen, K., Ferrand, D., Green, S. F., Jorda, L., Joven Álvarez, E., Knollenberg, J., Kührt, E., Lamy, P., Lellouch, E., Le Merrer, J., Marty, B., Mas, G., Rossin, C., Rozitis, B., Sunshine, J., Vernazza, P., and Vives, S.

Published
2016
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13. Surface changes on comet 67P/Churyumov-Gerasimenko suggest a more active past

Author

El-Maarry, M. Ramy, Groussin, O., Thomas, N., Pajola, M., Auger, A.-T., Davidsson, B., Hu, X., Hviid, S. F., Knollenberg, J., Güttler, C., Tubiana, C., Fornasier, S., Feller, C., Hasselmann, P., Vincent, J.-B., Sierks, H., Barbieri, C., Lamy, P., Rodrigo, R., Koschny, D., Keller, H. U., Rickman, H., A’Hearn, M. F., Barucci, M. A., Bertaux, J.-L., Bertini, I., Besse, S., Bodewits, D., Cremonese, G., Da Deppo, V., Debei, S., De Cecco, M., Deller, J., Deshapriya, J. D. P., Fulle, M., Gutierrez, P. J., Hofmann, M., Ip, W.-H., Jorda, L., Kovacs, G., Kramm, J.-R., Kührt, E., Küppers, M., Lara, L. M., Lazzarin, M., Lin, Z.-Yi, Lopez Moreno, J. J., Marchi, S., Marzari, F., Mottola, S., Naletto, G., Oklay, N., Pommerol, A., Preusker, F., Scholten, F., and Shi, X.

Published
2017
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15. Cometary dust analogues for physics experiments

Author

Lethuillier, A, primary, Feller, C, additional, Kaufmann, E, additional, Becerra, P, additional, Hänni, N, additional, Diethelm, R, additional, Kreuzig, C, additional, Gundlach, B, additional, Blum, J, additional, Pommerol, A, additional, Kargl, G, additional, Laddha, S, additional, Denisova, K, additional, Kührt, E, additional, Capelo, H L, additional, Haack, D, additional, Zhang, X, additional, Knollenberg, J, additional, Molinski, N S, additional, Gilke, T, additional, Sierks, H, additional, Tiefenbacher, P, additional, Güttler, C, additional, Otto, K A, additional, Bischoff, D, additional, Schweighart, M, additional, Hagermann, A, additional, and Jäggi, N, additional

Published
2022
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16. Šteins

Author

Kührt, E.

Subjects
asteroids, Šteins, Rosetta
Published
2022

17. The CoPhyLab comet-simulation chamber

Author

Kreuzig, C., primary, Kargl, G., additional, Pommerol, A., additional, Knollenberg, J., additional, Lethuillier, A., additional, Molinski, N. S., additional, Gilke, T., additional, Bischoff, D., additional, Feller, C., additional, Kührt, E., additional, Sierks, H., additional, Hänni, N., additional, Capelo, H., additional, Güttler, C., additional, Haack, D., additional, Otto, K., additional, Kaufmann, E., additional, Schweighart, M., additional, Macher, W., additional, Tiefenbacher, P., additional, Gundlach, B., additional, and Blum, J., additional

Published
2021
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18. The landing(s) of Philae and inferences about comet surface mechanical properties

Author

Biele, J., Ulamec, S., Maibaum, M., Roll, R., Witte, L., Jurado, E., Muñoz, P., Arnold, W., Auster, H.-U., Casas, C., Faber, C., Fantinati, C., Finke, F., Fischer, H.-H., Geurts, K., Güttler, C., Heinisch, P., Herique, A., Hviid, S., Kargl, G., Knapmeyer, M., Knollenberg, J., Kofman, W., Kömle, N., Kührt, E., Lommatsch, V., Mottola, S., Pardo de Santayana, R., Remetean, E., Scholten, F., Seidensticker, K. J., Sierks, H., and Spohn, T.

Published
2015

20. The nonmagnetic nucleus of comet 67P/Churyumov-Gerasimenko

Author

Auster, H.-U., Apathy, I., Berghofer, G., Fornacon, K.-H., Remizov, A., Carr, C., Güttler, C., Haerendel, G., Heinisch, P., Hercik, D., Hilchenbach, M., Kührt, E., Magnes, W., Motschmann, U., Richter, I., Russell, C. T., Przyklenk, A., Schwingenschuh, K., Sierks, H., and Glassmeier, K.-H.

Published
2015

21. The morphological diversity of comet 67P/Churyumov-Gerasimenko

Author

Thomas, N., Sierks, H., Barbieri, C., Lamy, P. L., Rodrigo, R., Rickman, H., Koschny, D., Keller, H. U., Agarwal, J., AʼHearn, M. F., Angrilli, F., Auger, A.-T., Barucci, M. A., Bertaux, J.-L., Bertini, I., Besse, S., Bodewits, D., Cremonese, G., Da Deppo, V., Davidsson, B., De Cecco, M., Debei, S., El-Maarry, M. R., Ferri, F., Fornasier, S., Fulle, M., Giacomini, L., Groussin, O., Gutierrez, P. J., Güttler, C., Hviid, S. F., Ip, W.-H., Jorda, L., Knollenberg, J., Kramm, J.-R., Kührt, E., Küppers, M., La Forgia, F., Lara, L. M., Lazzarin, M., Moreno, Lopez J. J., Magrin, S., Marchi, S., Marzari, F., Massironi, M., Michalik, H., Moissl, R., Mottola, S., Naletto, G., Oklay, N., Pajola, M., Pommerol, A., Preusker, F., Sabau, L., Scholten, F., Snodgrass, C., Tubiana, C., Vincent, J.-B., and Wenzel, K.-P.

Published
2015

22. Dust measurements in the coma of comet 67P/Churyumov-Gerasimenko inbound to the Sun

Author

Rotundi, A., Sierks, H., Corte, Della V., Fulle, M., Gutierrez, P. J., Lara, L., Barbieri, C., Lamy, P. L., Rodrigo, R., Koschny, D., Rickman, H., Keller, H. U., López-Moreno, J. J., Accolla, M., Agarwal, J., AʼHearn, M. F., Altobelli, N., Angrilli, F., Barucci, M. A., Bertaux, J.-L., Bertini, I., Bodewits, D., Bussoletti, E., Colangeli, L., Cosi, M., Cremonese, G., Crifo, J.-F., Da Deppo, V., Davidsson, B., Debei, S., De Cecco, M., Esposito, F., Ferrari, M., Fornasier, S., Giovane, F., Gustafson, B., Green, S. F., Groussin, O., Grün, E., Güttler, C., Herranz, M. L., Hviid, S. F., Ip, W., Ivanovski, S., Jerónimo, J. M., Jorda, L., Knollenberg, J., Kramm, R., Kührt, E., Küppers, M., Lazzarin, M., Leese, M. R., López-Jiménez, A. C., Lucarelli, F., Lowry, S. C., Marzari, F., Epifani, Mazzotta E., McDonnell, J. A. M., Mennella, V., Michalik, H., Molina, A., Morales, R., Moreno, F., Mottola, S., Naletto, G., Oklay, N., Ortiz, J. L., Palomba, E., Palumbo, P., Perrin, J.-M., Rodríguez, J., Sabau, L., Snodgrass, C., Sordini, R., Thomas, N., Tubiana, C., Vincent, J.-B., Weissman, P., Wenzel, K.-P., Zakharov, V., and Zarnecki, J. C.

Published
2015

23. On the nucleus structure and activity of comet 67P/Churyumov-Gerasimenko

Author

Sierks, H., Barbieri, C., Lamy, P. L., Rodrigo, R., Koschny, D., Rickman, H., Keller, H. U., Agarwal, J., AʼHearn, M. F., Angrilli, F., Auger, A.-T., Barucci, M. A., Bertaux, J.-L., Bertini, I., Besse, S., Bodewits, D., Capanna, C., Cremonese, G., Da Deppo, V., Davidsson, B., Debei, S., De Cecco, M., Ferri, F., Fornasier, S., Fulle, M., Gaskell, R., Giacomini, L., Groussin, O., Gutierrez-Marques, P., Gutiérrez, P. J., Güttler, C., Hoekzema, N., Hviid, S. F., Ip, W.-H., Jorda, L., Knollenberg, J., Kovacs, G., Kramm, J.-R., Kührt, E., Küppers, M., La Forgia, F., Lara, L. M., Lazzarin, M., Leyrat, C., Moreno, Lopez J. J., Magrin, S., Marchi, S., Marzari, F., Massironi, M., Michalik, H., Moissl, R., Mottola, S., Naletto, G., Oklay, N., Pajola, M., Pertile, M., Preusker, F., Sabau, L., Scholten, F., Snodgrass, C., Thomas, N., Tubiana, C., Vincent, J.-B., Wenzel, K.-P., Zaccariotto, M., and Pätzold, M.

Published
2015

24. Time variability and heterogeneity in the coma of 67P/Churyumov-Gerasimenko

Author

Hässig, M., Altwegg, K., Balsiger, H., Bar-Nun, A., Berthelier, J. J., Bieler, A., Bochsler, P., Briois, C., Calmonte, U., Combi, M., De Keyser, J., Eberhardt, P., Fiethe, B., Fuselier, S. A., Galand, M., Gasc, S., Gombosi, T. I., Hansen, K. C., Jäckel, A., Keller, H. U., Kopp, E., Korth, A., Kührt, E., Le Roy, L., Mall, U., Marty, B., Mousis, O., Neefs, E., Owen, T., Rème, H., Rubin, M., Sémon, T., Tornow, C., Tzou, C.-Y., Waite, J. H., and Wurz, P.

Published
2015

25. Triple F—a comet nucleus sample return mission

Author

Küppers, Michael, Keller, H. U., Kührt, E., A’Hearn, M. F., Altwegg, K., Bertrand, R., Busemann, H., Capria, M. T., Colangeli, L., Davidsson, B., Ehrenfreund, P., Knollenberg, J., Mottola, S., Rathke, A., Weiss, P., Zolensky, M., Akim, E., Basilevsky, A., Galimov, E., Gerasimov, M., Korablev, O., Lomakin, I., Marov, M., Martynov, M., Nazarov, M., Zakharov, A., Zelenyi, L., Aronica, A., Ball, A. J., Barbieri, C., Bar-Nun, A., Benkhoff, J., Biele, J., Biver, N., Blum, J., Bockelée-Morvan, D., Botta, O., Bredehöft, J.-H., Capaccioni, F., Charnley, S., Cloutis, E., Cottin, H., Cremonese, G., Crovisier, J., Crowther, S. A., Epifani, E. M., Esposito, F., Ferrari, A. C., Ferri, F., Fulle, M., Gilmour, J., Goesmann, F., Gortsas, N., Green, S. F., Groussin, O., Grün, E., Gutiérrez, P. J., Hartogh, P., Henkel, T., Hilchenbach, M., Ho, T.-M., Horneck, G., Hviid, S. F., Ip, W.-H., Jäckel, A., Jessberger, E., Kallenbach, R., Kargl, G., Kömle, N. I., Korth, A., Kossacki, K., Krause, C., Krüger, H., Li, Z.-Y., Licandro, J., Lopez-Moreno, J. J., Lowry, S. C., Lyon, I., Magni, G., Mall, U., Mann, I., Markiewicz, W., Martins, Z., Maurette, M., Meierhenrich, U., Mennella, V., Ng, T. C., Nittler, L. R., Palumbo, P., Pätzold, M., Prialnik, D., Rengel, M., Rickman, H., Rodriguez, J., Roll, R., Rost, D., Rotundi, A., Sandford, S., Schönbächler, M., Sierks, H., Srama, R., Stroud, R. M., Szutowicz, S., Tornow, C., Ulamec, S., Wallis, M., Waniak, W., Weissman, P., Wieler, R., Wurz, P., Yung, K. L., and Zarnecki, J. C.

Published
2009
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26. ROMAP: Rosetta Magnetometer and Plasma Monitor

Author

Auster, H. U., Apathy, I., Berghofer, G., Remizov, A., Roll, R., Fornacon, K. H., Glassmeier, K. H., Haerendel, G., Hejja, I., Kührt, E., Magnes, W., Moehlmann, D., Motschmann, U., Richter, I., Rosenbauer, H., Russell, C. T., Rustenbach, J., Sauer, K., Schwingenschuh, K., Szemerey, I., and Waesch, R.

Published
2007
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27. OSIRIS – The Scientific Camera System Onboard Rosetta

Author

Keller, H. U., Barbieri, C., Lamy, P., Rickman, H., Rodrigo, R., Wenzel, K.-P., Sierks, H., A’Hearn, M. F., Angrilli, F., Angulo, M., Bailey, M. E., Barthol, P., Barucci, M. A., Bertaux, J.-L., Bianchini, G., Boit, J.-L., Brown, V., Burns, J. A., Büttner, I., Castro, J. M., Cremonese, G., Curdt, W., Deppo, V. Da, Debei, S., Cecco, M. De, Dohlen, K., Fornasier, S., Fulle, M., Germerott, D., Gliem, F., Guizzo, G. P., Hviid, S. F., Ip, W.-H., Jorda, L., Koschny, D., Kramm, J. R., Kührt, E., Küppers, M., Lara, L. M., Llebaria, A., López, A., López-Jimenez, A., López-Moreno, J., Meller, R., Michalik, H., Michelena, M. D., Müller, R., Naletto, G., Origné, A., Parzianello, G., Pertile, M., Quintana, C., Ragazzoni, R., Ramous, P., Reiche, K.-U., Reina, M., Rodríguez, J., Rousset, G., Sabau, L., Sanz, A., Sivan, J.-P., Stöckner, K., Tabero, J., Telljohann, U., Thomas, N., Timon, V., Tomasch, G., Wittrock, T., and Zaccariotto, M.

Published
2007
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28. Studying the Composition and Mineralogy of the Hermean Surface with the Mercury Radiometer and Thermal Infrared Spectrometer (MERTIS) for the BepiColombo Mission: An Update

Author

Hiesinger, H, Helbert, J, Alemanno, G, Bauch, KE, D’Amore, M, Maturilli, A, Morlok, A, Reitze, MP, Stangarone, C, Stojic, AN, Varatharajan, I, Weber, I, Arnold, G, Banaszkiewicz, M, Bauch, K, Benkhoff, J, Bischoff, A, Blecka, M, Bowles, N, Calcutt, S, Colangeli, L, Erard, S, Fonti, S, Greenhagen, BT, Groussain, O, Hirsch, H, Jahn, J, Killen, R, Knollenberg, J, Kührt, E, Lorenz, E, Mann, I, Mall, U, Moroz, L, Peter, G, Rataj, M, Robinson, M, Skrbek, W, Spohn, T, Sprague, A, Stöffler, D, Stojic, A, Taylor, F, Venus, H, Warrell, J, and Walter, I

Subjects
Spectral signature, Radiometer, Spectrometer, Spacecraft, business.industry, BepiColombo, MERTIS instrument, Mineralogy, Astronomy and Astrophysics, Mercury, Space weathering, law.invention, Orbiter, Planetary science, Space and Planetary Science, Planet, law, Environmental science, business, Spectroscopy
Abstract

Launched onboard the BepiColombo Mercury Planetary Orbiter (MPO) in October 2018, the Mercury Radiometer and Thermal Infrared Spectrometer (MERTIS) is on its way to planet Mercury. MERTIS consists of a push-broom IR-spectrometer (TIS) and a radiometer (TIR), which operate in the wavelength regions of 7-14 μm and 7-40 μm, respectively. This wavelength region is characterized by several diagnostic spectral signatures: the Christiansen feature (CF), Reststrahlen bands (RB), and the Transparency feature (TF), which will allow us to identify and map rock-forming silicates, sulfides as well as other minerals. Thus, the instrument is particularly well-suited to study the mineralogy and composition of the hermean surface at a spatial resolution of about 500 m globally and better than 500 m for approximately 5-10% of the surface. The instrument is fully functional onboard the BepiColombo spacecraft and exceeds all requirements (e.g., mass, power, performance). To prepare for the science phase at Mercury, the team developed an innovative operations plan to maximize the scientific output while at the same time saving spacecraft resources (e.g., data downlink). The upcoming fly-bys will be excellent opportunities to further test and adapt our software and operational procedures. In summary, the team is undertaking action at multiple levels, including performing a comprehensive suite of spectroscopic measurements in our laboratories on relevant analog materials, performing extensive spectral modeling, examining space weathering effects, and modeling the thermal behavior of the hermean surface.

Published
2020
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29. Cometary dust analogues for physics experiments

Author

Lethuillier, A., Feller, C., Kaufmann, E., Becerra, P., Hänni, N., Diethelm, R., Kreuzig, C., Gundlach, B., Blum, J., Pommerol, A., Kargl, G., Kührt, E., Capelo, H., Haack, D., Zhang, X., Knollenberg, J., Molinski, N. S., Gilke, T., Sierks, H., Tiefenbacher, P., Güttler, C., Otto, K. A., Bischoff, D., Schweighart, M., Hagermann, A., Jäggi, N., Lethuillier, A., Feller, C., Kaufmann, E., Becerra, P., Hänni, N., Diethelm, R., Kreuzig, C., Gundlach, B., Blum, J., Pommerol, A., Kargl, G., Kührt, E., Capelo, H., Haack, D., Zhang, X., Knollenberg, J., Molinski, N. S., Gilke, T., Sierks, H., Tiefenbacher, P., Güttler, C., Otto, K. A., Bischoff, D., Schweighart, M., Hagermann, A., and Jäggi, N.

Abstract

The CoPhyLab (Cometary Physics Laboratory) project is designed to study the physics of comets through a series of earth-based experiments. For these experiments, a dust analogue was created with physical properties comparable to those of the non-volatile dust found on comets. This "CoPhyLab dust" is planned to be mixed with water and CO$_2$ ice and placed under cometary conditions in vacuum chambers to study the physical processes taking place on the nuclei of comets. In order to develop this dust analogue, we mixed two components representative for the non-volatile materials present in cometary nuclei. We chose silica dust as representative for the mineral phase and charcoal for the organic phase, which also acts as a darkening agent. In this paper, we provide an overview of known cometary analogues before presenting measurements of eight physical properties of different mixtures of the two materials and a comparison of these measurements with known cometary values. The physical properties of interest are: particle size, density, gas permeability, spectrophotometry, mechanical, thermal and electrical properties. We found that the analogue dust that matches the highest number of physical properties of cometary materials consists of a mixture of either 60\%/40\% or 70\%/30\% of silica dust/charcoal by mass. These best-fit dust analogue will be used in future CoPhyLab experiments.

Published
2021

32. OSIRIS: The Scientific Camera System Onboard Rosetta

Author

Keller, H. U., primary, Barbieri, C., additional, Lamy, P., additional, Rickman, H., additional, Rodrigo, R., additional, Wenzel, K. -P., additional, Sierks, H., additional, A’Hearn, M. F., additional, Angrilli, F., additional, Angulo, M., additional, Bailey, M. E., additional, Barthol, P., additional, Barucci, M. A., additional, Bertaux, J.-L., additional, Bianchini, G., additional, Boit, J.-L., additional, Brown, V., additional, Burns, J. A., additional, Büttner, I., additional, Castro, J. M., additional, Cremonese, G., additional, Curdt, W., additional, Deppo, V. Da, additional, Debei, S., additional, Cecco, M. De, additional, Dohlen, K., additional, Fornasier, S., additional, Fulle, M., additional, Germerott, D., additional, Gliem, F., additional, Guizzo, G. P., additional, Hviid, S. F., additional, Ip, W.-H., additional, Jorda, L., additional, Koschny, D., additional, Kramm, J. R., additional, Kührt, E., additional, Küppers, M., additional, Lara, L. M., additional, Llebaria, A., additional, López, A., additional, López-Jimenez, A., additional, López-Moreno, J., additional, Meller, R., additional, Michalik, H., additional, Michelena, M. D., additional, Müller, R., additional, Naletto, G., additional, Origné, A., additional, Parzianello, G., additional, Pertile, M., additional, Quintana, C., additional, Ragazzoni, R., additional, Ramous, P., additional, Reiche, K.-U., additional, Reina, M., additional, Rodríguez, J., additional, Rousset, G., additional, Sabau, L., additional, Sanz, A., additional, Sivan, J.-P., additional, Stöckner, K., additional, Tabero, J., additional, Telljohann, U., additional, Thomas, N., additional, Timon, V., additional, Tomasch, G., additional, and Wittrock, T., additional

Published
2009
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33. Rosetta Lander (“Philae”) Investigations

Author

Bibring, J.-P., primary, Rosenbauer, H., additional, Boehnhardt, H., additional, Ulamec, S., additional, Biele, J., additional, Espinasse, S., additional, Feuerbacher, B., additional, Gaudon, P., additional, Hemmerich, P., additional, Kletzkine, P., additional, Moura, D., additional, Mugnuolo, R., additional, Nietner, G., additional, Pätz, B., additional, Roll, R., additional, Scheuerle, H., additional, Szegö, K., additional, Wittmann, K., additional, team, Philae, additional, Klingelhöfer, G., additional, Brückner, J., additional, d’Uston, C., additional, Gellert, R., additional, Rieder, R., additional, López, J. Gironés, additional, Bibring, J.-P., additional, Lamy, P., additional, Langevin, Y., additional, Soufflot, A., additional, Berthé, M., additional, Borg, J., additional, Poulet, F., additional, Mottola, S., additional, Goesmann, Fred, additional, Rosenbauer, Helmut, additional, Roll, Reinhard, additional, Szopa, Cyril, additional, Raulin, Francois, additional, Sternberg, Robert, additional, Israel, Guy, additional, Meierhenrich, Uwe, additional, Thiemann, Wolfram, additional, Munoz-Caro, Guillermo, additional, Spohn, Tilman, additional, Seiferlin, Karsten, additional, Hagermann, Axel, additional, Knollenberg, Jörg, additional, Ball, Andrew J., additional, Breuer, Doris, additional, Banaszkiewicz, Marek, additional, Benkhoff, Johannes, additional, Gadomski, Stanislaw, additional, Gregorczyk, Wojciech, additional, Grygorczuk, Jerzy, additional, Hlond, Marek, additional, Kargl, Günter, additional, Kührt, Ekkehard, additional, Kömle, Norbert, additional, Kossacki, Konrad, additional, Krasowski, Jacek, additional, Marczewski, Wojciech, additional, Zarnecki, John C., additional, Morse, A. D., additional, Morgan, G. H., additional, Andrews, D. J., additional, Barber, S. J., additional, Leese, M. R., additional, Sheridan, S., additional, Wright, I. P., additional, Pillinger, C. T., additional, Mottola, Stefano, additional, Arnold, Gabriele, additional, Grothues, Hans-Georg, additional, Jaumann, Ralf, additional, Michaelis, Harald, additional, Neukum, Gerhard, additional, Bibring, Jean-Pierre, additional, Auster, H.U., additional, Apathy, I., additional, Berghofer, G., additional, Remizov, A., additional, Fornacon, K.H., additional, Glassmeier, K.H., additional, Haerendel, G., additional, Hejja, I., additional, Kührt, E., additional, Magnes, W., additional, Moehlmann, D., additional, Motschmann, U., additional, Richter, I., additional, Russell, C.T., additional, Rustenbach, J., additional, Sauer, K., additional, Schwingenschuh, K., additional, Szemerey, I., additional, Waesch, R., additional, Zazzera, F. Bernelli, additional, Bologna, P., additional, Dainese, C., additional, Finzi, A. Ercoli, additional, Magnani, P.G., additional, Malnati, F., additional, Olivieri, A., additional, Re, E., additional, Seidensticker, K. J., additional, Möhlmann, D., additional, Schmidt, W., additional, Thiel, K., additional, Arnold, W., additional, Fischer, H.-H., additional, Kretschmer, M., additional, Péter, A., additional, Trautner, R., additional, and Schieke, S., additional

Published
2009
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35. Images of Asteroid 21 Lutetia: A Remnant Planetesimal from the Early Solar System

Author

Sierks, H., Lamy, P., Barbieri, C., Koschny, D., Rickman, H., Rodrigo, R., AʼHearn, M. F., Angrilli, F., Barucci, M. A., Bertaux, J. L., Bertini, I., Besse, S., Carry, B., Cremonese, G., Da Deppo, V., Davidsson, B., Debei, S., De Cecco, M., De Leon, J., Ferri, F., Fornasier, S., Fulle, M., Hviid, S. F., Gaskell, R. W., Groussin, O., Gutierrez, P., Ip, W., Jorda, L., Kaasalainen, M., Keller, H. U., Knollenberg, J., Kramm, R., Kührt, E., Küppers, M., Lara, L., Lazzarin, M., Leyrat, C., Moreno, Lopez J. J., Magrin, S., Marchi, S., Marzari, F., Massironi, M., Michalik, H., Moissl, R., Naletto, G., Preusker, F., Sabau, L., Sabolo, W., Scholten, F., Snodgrass, C., Thomas, N., Tubiana, C., Vernazza, P., Vincent, J. B., Wenzel, K. P., Andert, T., Pätzold, M., and Weiss, B. P.

Published
2011
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36. Time evolution of dust deposits in the Hapi region of comet 67P/Churyumov-Gerasimenko

Author

Cambianica, P., primary, Fulle, M., additional, Cremonese, G., additional, Simioni, E., additional, Naletto, G., additional, Massironi, M., additional, Penasa, L., additional, Lucchetti, A., additional, Pajola, M., additional, Bertini, I., additional, Bodewits, D., additional, Ceccarelli, C., additional, Ferri, F., additional, Fornasier, S., additional, Frattin, E., additional, Güttler, C., additional, Gutiérrez, P. J., additional, Keller, H. U., additional, Kührt, E., additional, Küppers, M., additional, La Forgia, F., additional, Lazzarin, M., additional, Marzari, F., additional, Mottola, S., additional, Sierks, H., additional, Toth, I., additional, Tubiana, C., additional, and Vincent, J.-B., additional

Published
2020
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37. E-Type Asteroid (2867) Steins as Imaged by OSIRIS on Board Rosetta

Author

Keller, H. U., Barbieri, C., Koschny, D., Lamy, P., Rickman, H., Rodrigo, R., Sierks, H., AʼHearn, M. F., Angrilli, F., Barucci, M. A., Bertaux, J.-L., Cremonese, G., Da Deppo, V., Davidsson, B., De Cecco, M., Debei, S., Fornasier, S., Fulle, M., Groussin, O., Gutierrez, P. J., Hviid, S. F., Ip, W.-H., Jorda, L., Knollenberg, J., Kramm, J. R., Kührt, E., Küppers, M., Lara, L.-M., Lazzarin, M., Moreno, J. Lopez, Marzari, F., Michalik, H., Naletto, G., Sabau, L, Thomas, N., Wenzel, K.-P., Bertini, I., Besse, S., Ferri, F., Kaasalainen, M., Lowry, S., Marchi, S., Mottola, S., Sabolo, W., Schröder, S. E., Spjuth, S., and Vernazza, P.

Published
2010
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43. Time evolution of dust deposits in the Hapi region of comet 67P/Churyumov-Gerasimenko

Author

German Centre for Air and Space Travel, Centre National de la Recherche Scientifique (France), Agenzia Spaziale Italiana, Ministerio de Ciencia, Innovación y Universidades (España), Government of Sweden, Cambianica, P., Fulle, M., Cremonese, G., Simioni, E., Naletto, G., Massironi, M., Penasa, L., Lucchetti, A., Pajola, M., Bertini, I., Bodewits, D., Ceccarelli, C., Ferri, F., Fornasier, S., Frattin, E., Güttler, C., Gutiérrez, Pedro J., Keller, H.U., Kührt, E., Küppers, M., La Forgia, F., Lazzarin, M., Marzari, F., Mottola, S., Sierks, H., Toth, I., Tubiana, C., Vincent, J.B., German Centre for Air and Space Travel, Centre National de la Recherche Scientifique (France), Agenzia Spaziale Italiana, Ministerio de Ciencia, Innovación y Universidades (España), Government of Sweden, Cambianica, P., Fulle, M., Cremonese, G., Simioni, E., Naletto, G., Massironi, M., Penasa, L., Lucchetti, A., Pajola, M., Bertini, I., Bodewits, D., Ceccarelli, C., Ferri, F., Fornasier, S., Frattin, E., Güttler, C., Gutiérrez, Pedro J., Keller, H.U., Kührt, E., Küppers, M., La Forgia, F., Lazzarin, M., Marzari, F., Mottola, S., Sierks, H., Toth, I., Tubiana, C., and Vincent, J.B.

Abstract

Aims. We provide a measurement of the seasonal evolution of the dust deposit erosion and accretion in the Hapi region of comet 67P/Churyumov-Gerasimenko with a vertical accuracy of 0.2-0.9 m. Methods. We used OSIRIS Narrow Angle Camera images with a spatial scale of lower than 1.30 m px-1 and developed a tool to monitor the time evolution of 22 boulder heights with respect to the surrounding dust deposit. The tool is based on the measurement of the shadow length projected by the boulder on the surrounding pebble deposit. Assuming the position of the boulders does not change during the observational period, boulder height variations provide an indication of how the thickness of the surrounding dust layer varies over time through erosion and accretion phenomena. Results. We measured an erosion of the dust deposit of 1.7 ± 0.2 m during the inbound orbit until 12 December, 2014. This value nearly balances the fallout from the southern hemisphere during perihelion cometary activity. During the perihelion phase, the dust deposit then increased by 1.4 ± 0.8 m. This is interpreted as a direct measurement of the fallout thickness. By comparing the erosion rate and dust volume loss rate at the Hapi region measured in the coma, the fallout represents ~96% in volume of the ejecta. The amount of the eroded pristine material from the southern hemisphere, together with its subsequent transport and fallout on the nucleus, led us to discuss the pristine water ice abundance in comet 67P. We determine that the refractory-to-ice mass ratio ranges from 6 to 110 in the perihelion-eroded pristine nucleus, providing a pristine ice mass fraction of (8 ± 7)% in mass. © 2020 ESO.

Published
2020

47. Experimental simulation of cometary surfaces using volatile-rich analogue materials

Author

Haack, David, Otto, Katharina A., Kührt, E., Gundlach, Bastian, Kreuzig, Christopher, and Blum, Jürgen

Subjects
Asteroiden und Kometen, sublimation, cometary surfaces
Abstract

Cometary surfaces are shaped through the process of activity when the comet approaches the sun and the sublimation of volatiles removes dust and gases. Recently, the ESA Rosetta mission showed the geomorphologic diversity of comet 67P/Churyumov-Gerasimenko in great detail (Fig. 1), giving us the opportunity to investigate the sublimation processes on small Solar System bodies by means of geomorphologic analyses of the surface . In order to understand how these processes alter the surface appearance, we investigate the morphologic evolution of sublimating cometary surfaces in the laboratory of the IGEP department at TU Braunschweig. The focus lies on the evolution of different morphologies that were found on comet 67P/Churyumov-Gerasimenko, such as fractur es and debris deposits [1,2]. We consider the composition and initial geometry of the samples and variable insolation flux. Different sample compositions and geometries are prepared to model the interaction of volatile-dust mixtures with vacuum conditions. The results will not only provide information on the material properties and parameters (e.g. cohesion, tensile strength) of comets, but will also enable us to Analyse the morphologic evolution of cometary surfaces.

Published
2019

48. Tensile strength of 67P/Churyumov–Gerasimenko nucleus material from overhangs

Author

Attree , N., Groussin , O., Jorda , L., Nébouy , D., Thomas , N., Brouet , Y., Kührt , E., Preusker , F., Scholten , F., Knollenberg , J., Hartogh , P., Sierks , H., Barbieri , C., Lamy , P., Rodrigo , R., Koschny , D., Rickman , H., Keller , H. U., A'Hearn , M. F., Auger , A.-T., Barucci , M. A., Bertaux , J.-L., Bertini , I., Bodewits , D., Boudreault , S., Cremonese , G., Da Deppo , V., Davidsson , B., Debei , S., De Cecco , M., Deller , J., El-Maarry , M. R., Fornasier , S., Fulle , M., Gutiérrez , P. J., Güttler , C., Hviid , S., Ip , W.-H., Kovacs , G., Kramm , J. R., Küppers , M., Lara , L. M., Lazzarin , M., Lopez Moreno , J. J., Lowry , S., Marchi , S., Marzari , F., Mottola , S., Naletto , G., Oklay , N., Pajola , M., Toth , I., Tubiana , C., Vincent , J.-B., Shi , X., A’Hearn , M., Gutierrez , J., Lara , M., Laboratoire d'Astrophysique de Marseille ( LAM ), Aix Marseille Université ( AMU ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National d'Etudes Spatiales ( CNES ) -Centre National de la Recherche Scientifique ( CNRS ), Physikalisches Institut [Bern], Universität Bern [Bern], DLR Institute of Planetary Research, German Aerospace Center ( DLR ), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] ( DLR ), Max-Planck-Institut für Sonnensystemforschung ( MPS ), Dipartimento di Fisica e Astronomia 'Galileo Galilei', Universita degli Studi di Padova, Research and Scientific Support Department, ESTEC ( RSSD ), European Space Research and Technology Centre ( ESTEC ), European Space Agency ( ESA ) -European Space Agency ( ESA ), Space Research Centre [Warsaw] ( CBK ), Polska Akademia Nauk ( PAN ), Department of Astronomy [College Park], University of Maryland [College Park], Laboratoire d'études spatiales et d'instrumentation en astrophysique ( LESIA ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université Paris Diderot - Paris 7 ( UPD7 ) -Centre National de la Recherche Scientifique ( CNRS ), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' ( CISAS ), INAF - Osservatorio Astronomico di Padova ( OAPD ), Istituto Nazionale di Astrofisica ( INAF ), CNR Institute for Photonics and Nanotechnologies ( IFN ), Consiglio Nazionale delle Ricerche [Roma] ( CNR ), Department of Physics and Astronomy [Uppsala], Uppsala University, INAF - Osservatorio Astronomico di Trieste ( OAT ), Instituto de Astrofísica de Andalucía ( IAA ), Consejo Superior de Investigaciones Científicas [Spain] ( CSIC ), Space Science Institute [Macau] ( SSI ), Macau University of Science and Technology ( MUST ), European Space Astronomy Center ( ESAC ), European Space Agency ( ESA ), Centre for Astrophysics and Planetary Science [Canterbury] ( CAPS ), University of Kent [Canterbury], Solar System Exploration Research Virtual Institute ( SSERVI ), Southwest Research Institute [Boulder] ( SwRI ), Istituto Nazionale di Fisica Nucleare, Sezione di Padova ( INFN, Sezione di Padova ), National Institute for Nuclear Physics ( INFN ), Institut des Sciences Chimiques de Rennes ( ISCR ), Université de Rennes 1 ( UR1 ), Université de Rennes ( UNIV-RENNES ) -Université de Rennes ( UNIV-RENNES ) -Ecole Nationale Supérieure de Chimie de Rennes-Institut National des Sciences Appliquées ( INSA ) -Centre National de la Recherche Scientifique ( CNRS ), Institute for Nanoscale Physics and Chemistry ( INPAC ), and Katholieke Universiteit Leuven ( KU Leuven )

Subjects
Methods: observational, comets: general, [ SDU.ASTR.EP ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], comets: individual: Churyumov-Gerasimenko
Abstract

International audience; We directly measured twenty overhanging cliffs on the surface of comet 67P/Churyumov-Gerasimenko extracted from the latest shape model and estimated the minimum tensile strengths needed to support them against collapse under the comet's gravity. We find extremely low strengths of around 1 Pa or less (1 to 5 Pa, when scaled to a metre length). The presence of eroded material at the base of most overhangs, as well as the observed collapse of two features andthe implied previous collapse of another, suggests that they are prone to failure and that the true material strengths are close to these lower limits (although we only consider static stresses and not dynamic stress from, for example, cometary activity). Thus, a tensile strength of a few pascals is a good approximation for the tensile strength of the 67P nucleus material, which is in agreement with previous work. We find no particular trends in overhang properties either with size over the 10-100 m range studied here or location on the nucleus. There are no obvious differences, in terms of strength, height or evidence of collapse, between the populations of overhangs on the two cometary lobes, suggesting that 67P is relatively homogenous in terms of tensile strength. Low material strengths are supportive of cometary formation as a primordial rubble pile or by collisional fragmentation of a small body (tens of km).

Published
2018
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49. Meter-scale thermal contraction crack polygons on the nucleus of comet 67P/Churyumov-Gerasimenko

Author

Auger , A.-T., Groussin , O., Jorda , L., El-Maarry , M. R., Bouley , S., Sejourne , A., Gaskell , R., Capanna , C., Davidsson , B., Marchi , S., Höfner , S., Lamy , P. L., Sierks , H., Barbieri , C., Rodrigo , R., Koschny , D., Rickman , H., Keller , H. U., Agarwal , J., A'Hearn , M. F., Barucci , M. A., Bertaux , J.-L., Bertini , I., Cremonese , G., Da Deppo , V., Debei , S., De Cecco , M., Fornasier , S., Fulle , M., Gutiérrez , P. J., Güttler , C., Hviid , S., Ip , W.-H., Knollenberg , J., Kramm , J.-R., Kührt , E., Küppers , M., Lara , L. M., Lazzarin , M., Lopez Moreno , J. J., Marzari , F., Massironi , M., Michalik , H., Naletto , G., Oklay , N., Pommerol , A., Sabau , L., Thomas , N., Tubiana , C., Vincent , J.-B., Wenzel , K.-P., Lamy , L., A’Hearn , M., Barucci , A., BERTAUX , L., Gutierrez , J., Ip , H., Laboratoire d'Astrophysique de Marseille ( LAM ), Aix Marseille Université ( AMU ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National d'Etudes Spatiales ( CNES ) -Centre National de la Recherche Scientifique ( CNRS ), Physikalisches Institut [Bern], Universität Bern [Bern], Institut de Mécanique Céleste et de Calcul des Ephémérides ( IMCCE ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université de Lille-Centre National de la Recherche Scientifique ( CNRS ), Interactions et dynamique des environnements de surface ( IDES ), Université Paris-Sud - Paris 11 ( UP11 ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Planetary Science Institute [Tucson] ( PSI ), Department of Physics and Astronomy [Uppsala], Uppsala University, Solar System Exploration Research Virtual Institute ( SSERVI ), Southwest Research Institute [Boulder] ( SwRI ), Max-Planck-Institut für Sonnensystemforschung ( MPS ), Dipartimento di Fisica e Astronomia 'Galileo Galilei', Universita degli Studi di Padova, Research and Scientific Support Department, ESTEC ( RSSD ), European Space Research and Technology Centre ( ESTEC ), European Space Agency ( ESA ) -European Space Agency ( ESA ), Space Research Centre [Warsaw] ( CBK ), Polska Akademia Nauk ( PAN ), European Space Agency ( ESA ), Department of Astronomy [College Park], University of Maryland [College Park], Laboratoire d'études spatiales et d'instrumentation en astrophysique ( LESIA ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université Paris Diderot - Paris 7 ( UPD7 ) -Centre National de la Recherche Scientifique ( CNRS ), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' ( CISAS ), INAF - Osservatorio Astronomico di Padova ( OAPD ), Istituto Nazionale di Astrofisica ( INAF ), CNR Institute for Photonics and Nanotechnologies ( IFN ), Consiglio Nazionale delle Ricerche [Roma] ( CNR ), INAF - Osservatorio Astronomico di Trieste ( OAT ), Instituto de Astrofísica de Andalucía ( IAA ), Consejo Superior de Investigaciones Científicas [Spain] ( CSIC ), DLR Institute of Planetary Research, German Aerospace Center ( DLR ), Space Science Institute [Macau] ( SSI ), Macau University of Science and Technology ( MUST ), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] ( DLR ), European Space Astronomy Center ( ESAC ), Istituto Nazionale di Fisica Nucleare, Sezione di Padova ( INFN, Sezione di Padova ), National Institute for Nuclear Physics ( INFN ), Dipartimento di Geoscienze [Padova], Institut für Datentechnik und Kommunikationsnetze, Technische Universität Braunschweig [Braunschweig], Instituto Nacional de Técnica Aeroespacial ( INTA ), Institute for Nanoscale Physics and Chemistry ( INPAC ), and Katholieke Universiteit Leuven ( KU Leuven )

Subjects
Comets, Geological processes, [ SDU.ASTR.EP ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Nucleus, [ SDU ] Sciences of the Universe [physics], [ SDU.ASTR ] Sciences of the Universe [physics]/Astrophysics [astro-ph]
Abstract

International audience; 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 (from North to South) and longitudes (head, neck, and body), sometimes on pit walls or following lineaments. About 1.5% of the observed surface is covered by polygons. Polygons have an homogeneous size across the nucleus, with 90% of them in the size range 1 - 5 m and a mean size of 3.0 ± 1.4 m. They show different morphologies, depending on the width and depth of their trough. They are found in networks with 3- or 4-crack intersection nodes. The polygons observed on 67P are consistent with thermal contraction crack polygons formed by the diurnal or seasonal temperature variations in a hard (MPa) and consolidated sintered layer of water ice, located a few centimeters below the surface. Our thermal analysis shows an evolution of thermal contraction crack polygons according to the local thermal environment, with more evolved polygons (i.e. deeper and larger troughs) where the temperature and the diurnal and seasonal temperature range are the highest. Thermal contraction crack polygons are young surface morphologies that probably formed after the injection of 67P in the inner solar system, typically 100,000 years ago, and could be as young as a few orbital periods, following the decreasing of its perihelion distance in 1959 from 2.7 to 1.3 a.u. Meter scale thermal contraction crack polygons should be common features on the nucleus of Jupiter family comets.

Published
2018
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