25 results on '"Kramm, J. -Rainer"'
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2. A Marconi CCD42-40 with Anti-Blooming : Experiences with the OSIRIS CCDs for the ROSETTA Mission
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Kramm, J. Rainer, Keller, Horst Uwe, Müller, Reinhard, Germerott, Dietmar, Tomasch, Georg, Burton, W. B., editor, Kuijpers, J. M. E., editor, Van Den Heuvel, E. P. J., editor, Van Der Laan, H., editor, Amico, Paola, editor, Beletic, James W., editor, and Beletic, Jenna E., editor
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- 2004
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3. CCDs for the Rosetta Science Imaging System OSIRIS
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Kramm, J. Rainer, Keller, H. Uwe, Amico, Paola, editor, and Beletic, James W., editor
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- 2000
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4. The CCD imager electronics for the Mars pathfinder and Mars surveyor cameras
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Kramm, J. Rainer, Thomas, Nicolas, Keller, H. Uwe, and Smith, Peter H.
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Mars Pathfinder (Space probe) -- Equipment and supplies ,Charge coupled devices -- Design and construction ,Electronic cameras -- Design and construction ,Analog to digital converters -- Design and construction ,Image processing -- Digital techniques - Published
- 1998
5. CCDs for the Rosetta Science Imaging System OSIRIS
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Kramm, J. Rainer, primary and Keller, H. Uwe, additional
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- 2000
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6. The southern hemisphere of 67P/Churyumov-Gerasimenko : Analysis of the preperihelion size-frequency distribution of boulders >= 7m
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Pajola, Maurizio, Lucchetti, Alice, Vincent, Jean-Baptiste, Oklay, Nilda, El-Maarry, Mohamed R., Bertini, Ivano, Naletto, Giampiero, Lazzarin, Monica, Massironi, Matteo, Sierks, Holger, Barbieri, Cesare, Lamy, Philippe, Rodrigo, Rafael, Koschny, Detlef, Rickman, Hans, Keller, Horst U., Agarwal, Jessica, A'Hearn, Michael F., Barucci, Maria A., Bertaux, Jean-Loup, Boudreault, Steve, Cremonese, Gabriele, Da Deppo, Vania, Davidsson, Bjorn, Debei, Stefano, De Cecco, Mariolino, Deller, Jakob, Fornasier, Sonia, Fulle, Marco, Gicquel, Adeline, Groussin, Olivier, Gutierrez, Pedro J., Guetler, Carsten, Hofmann, Marc, Hoefner, Sebastian, Hviid, Stubbe F., Ip, Wing-Huen, Jorda, Laurent, Knollenberg, Joerg, Kramm, J. -Rainer, Kuehrt, Ekkehard, Kuppers, Michael, La Forgia, Fiorangela, Lara, Luisa M., Lee, Jui-Chi, Lin, Zhong-Yi, Lopez Moreno, Jose J., Marzari, Francesco, Michalik, Harald, Mottola, Stefano, Preusker, Frank, Scholten, Frank, Thomas, Nicholas, Toth, Imre, Tubiana, Cecilia, Pajola, Maurizio, Lucchetti, Alice, Vincent, Jean-Baptiste, Oklay, Nilda, El-Maarry, Mohamed R., Bertini, Ivano, Naletto, Giampiero, Lazzarin, Monica, Massironi, Matteo, Sierks, Holger, Barbieri, Cesare, Lamy, Philippe, Rodrigo, Rafael, Koschny, Detlef, Rickman, Hans, Keller, Horst U., Agarwal, Jessica, A'Hearn, Michael F., Barucci, Maria A., Bertaux, Jean-Loup, Boudreault, Steve, Cremonese, Gabriele, Da Deppo, Vania, Davidsson, Bjorn, Debei, Stefano, De Cecco, Mariolino, Deller, Jakob, Fornasier, Sonia, Fulle, Marco, Gicquel, Adeline, Groussin, Olivier, Gutierrez, Pedro J., Guetler, Carsten, Hofmann, Marc, Hoefner, Sebastian, Hviid, Stubbe F., Ip, Wing-Huen, Jorda, Laurent, Knollenberg, Joerg, Kramm, J. -Rainer, Kuehrt, Ekkehard, Kuppers, Michael, La Forgia, Fiorangela, Lara, Luisa M., Lee, Jui-Chi, Lin, Zhong-Yi, Lopez Moreno, Jose J., Marzari, Francesco, Michalik, Harald, Mottola, Stefano, Preusker, Frank, Scholten, Frank, Thomas, Nicholas, Toth, Imre, and Tubiana, Cecilia
- Abstract
Aims. We calculate the size-frequency distribution of the boulders on the southern hemisphere of comet 67P Churyumov-Gerasimenko (67P), which was in shadow before the end of April 2015. We compare the new results with those derived from the northern hemisphere and equatorial regions of 67P, highlighting the possible physical processes that lead to these boulder size distributions. Methods. We used images acquired by the OSIRIS Narrow Angle Camera (NAC) on 2 May 2015 at a distance of 125 km from the nucleus. The scale of this dataset is 2.3 m/px; the high resolution of the images, coupled with the favorable observation phase angle of 62 degrees, provided the possibility to unambiguously identify boulders >= 7 m on the surface of 67P and to manually extract them with the software ArcGIS. We derived the size-frequency distribution of the illuminated southern hemisphere. Results. We found a power-law index of -3.6 +/- 0.2 for the boulders on the southern hemisphere with a diameter range of 7-35 m. The power-law index is equal to the one previously found on northern and equatorial regions of 67P, suggesting that similar boulder formation processes occur in both hemispheres. The power-law index is related to gravitational events triggered by sublimation and/or thermal fracturing causing regressive erosion. In addition, the presence of a larger number of boulders per km(2) in the southern hemisphere, which is a factor of 3 higher with respect to the northern hemisphere, suggests that the southernmost terrains of 67P are affected by a stronger thermal fracturing and sublimating activity, hence possibly causing larger regressive erosion and gravitational events.
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- 2016
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7. Aswan site on comet 67P/Churyumov-Gerasimenko : Morphology, boulder evolution, and spectrophotometry
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Pajola, Maurizio, Oklay, Nilda, La Forgia, Fiorangela, Giacomini, Lorenza, Massironi, Matteo, Bertini, Ivano, El-Maarry, M. R., Marzari, Francesco, Preusker, Frank, Scholten, Frank, Hoefner, Sebastian, Lee, Jui-Chi, Vincent, Jean-Baptiste, Groussin, Olivier, Naletto, Giampiero, Lazzarin, Monica, Barbieri, Cesare, Sierks, Holger, Lamy, Philippe, Rodrigo, Rafael, Koschny, Detlef, Rickman, Hans, Keller, Horst U., Agarwal, Jessica, A'Hearn, Michael F., Barucci, Maria A., Bertaux, Jean-Loup, Cremonese, Gabriele, Da Deppoll, Vania, Davidsson, Bjoern, De Cecco, Mariolino, Debei, Stefano, Ferri, Francesca, Fornasier, Sonia, Fulle, Marco, Guettler, Carsten, Gutierrez, Pedro J., Hviid, Stubbe F., Ip, Wing-Huen, Jorda, Laurent, Knollenberg, Joerg, Kramm, J. -Rainer, Kueppers, Michael, Kuert, Ekkehard, Lara, Luisa M., Lin, Zhong-Yi, Moreno, Jose J. Lopez, Magrin, Sara, Michalik, Harald, Mottola, Stefano, Thomas, Nicholas, Tubiana, Cecilia, Pajola, Maurizio, Oklay, Nilda, La Forgia, Fiorangela, Giacomini, Lorenza, Massironi, Matteo, Bertini, Ivano, El-Maarry, M. R., Marzari, Francesco, Preusker, Frank, Scholten, Frank, Hoefner, Sebastian, Lee, Jui-Chi, Vincent, Jean-Baptiste, Groussin, Olivier, Naletto, Giampiero, Lazzarin, Monica, Barbieri, Cesare, Sierks, Holger, Lamy, Philippe, Rodrigo, Rafael, Koschny, Detlef, Rickman, Hans, Keller, Horst U., Agarwal, Jessica, A'Hearn, Michael F., Barucci, Maria A., Bertaux, Jean-Loup, Cremonese, Gabriele, Da Deppoll, Vania, Davidsson, Bjoern, De Cecco, Mariolino, Debei, Stefano, Ferri, Francesca, Fornasier, Sonia, Fulle, Marco, Guettler, Carsten, Gutierrez, Pedro J., Hviid, Stubbe F., Ip, Wing-Huen, Jorda, Laurent, Knollenberg, Joerg, Kramm, J. -Rainer, Kueppers, Michael, Kuert, Ekkehard, Lara, Luisa M., Lin, Zhong-Yi, Moreno, Jose J. Lopez, Magrin, Sara, Michalik, Harald, Mottola, Stefano, Thomas, Nicholas, and Tubiana, Cecilia
- Abstract
Aims. We provide a detailed morphological analysis of the Aswan site on comet 67P/Churyumov-Gerasimenko (67P). We derive the size-frequency distribution of boulders >= 2 m and correlate this distribution with the gravitational slopes for the first time on a comet. We perform the spectral analysis of this region to understand if possible surface variegation is related to the different surface textures observable on the different units. Methods. We used two OSIRIS Narrow Angle Camera (NAC) image data sets acquired on September 19 and 22, 2014, with a scale of 0.5 m/px. Gravitational slopes derived from the 3D shape model of 67P were used to identify and interpret the different units of the site. By means of the high-resolution NAC data sets, boulders >= 2.0 m can be unambiguously identified and extracted using the software ArcGIS. Coregistered and photometrically corrected color cubes were used to perform the spectral analyses, and we retrieved the spectral properties of the Aswan units. Results. The high-resolution morphological map of the Aswan site (0.68 km(2)) shows that this site is characterized by four different units: fine-particle deposits located on layered terrains, gravitational accumulation deposits, taluses, and the outcropping layered terrain. Multiple lineaments are identified on the Aswan cliff, such as fractures, exposed layered outcrops, niches, and terraces. Close to the terrace margin, several arched features observed in plan view suggest that the margin progressively retreats as a result of erosion. The size-frequency of boulders >= 2 m in the entire study area has a power-law index of -3.9 +0.2/-0.3 (1499 boulders >= 2 m/km(2)), suggesting that the Aswan site is mainly dominated by gravitational events triggered by sublimation and/or thermal insolation weathering causing regressive erosion. The boulder size-frequency distribution versus gravitational slopes indicates that when higher gravitational slope terrains are considered, only
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- 2016
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8. Gas outflow and dust transport of comet 67P/Churyumov-Gerasimenko
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Lai, Ian-Lin, Ip, Wing-Huen, Su, Cheng-Chin, Wu, Jong-Shinn, Lee, Jui-Chi, Lin, Zhong-Yi, Liao, Ying, Thomas, Nicolas, Sierks, Holger, Barbieri, Cesare, Lamy, Philippe, Rodrigo, Rafael, Koschny, Detlef, Rickman, Hans, Keller, Horst Uwe, Agarwal, Jessica, A'Hearn, Michael F., Barucci, Maria Antonella, Bertaux, Jean-Loup, Bertini, Ivano, Boudreault, Steven, Cremonese, Gabriele, Da Deppo, Vania, Davidsson, Björn, Debei, Stefano, De Cecco, Mariolino, Deller, Jakob, Fornasier, Sonia, Fulle, Marco, Groussin, Olivier, Gutierrez, Pedro J., Guttler, Carsten, Hofmann, Marc, Hviid, Stubbe F., Jorda, Laurent, Knollenberg, J. Org, Kovacs, Gabor, Kramm, J. -Rainer, Kuhrt, Ekkehard, Kuppers, Michael, Lara, Luisa M., Lazzarin, Monica, Moreno, Jose J. Lopez, Marzari, Francesco, Naletto, Giampiero, Oklay, Nilda, Shi, Xian, Tubiana, Cecilia, Vincent, Jean-Baptiste, Lai, Ian-Lin, Ip, Wing-Huen, Su, Cheng-Chin, Wu, Jong-Shinn, Lee, Jui-Chi, Lin, Zhong-Yi, Liao, Ying, Thomas, Nicolas, Sierks, Holger, Barbieri, Cesare, Lamy, Philippe, Rodrigo, Rafael, Koschny, Detlef, Rickman, Hans, Keller, Horst Uwe, Agarwal, Jessica, A'Hearn, Michael F., Barucci, Maria Antonella, Bertaux, Jean-Loup, Bertini, Ivano, Boudreault, Steven, Cremonese, Gabriele, Da Deppo, Vania, Davidsson, Björn, Debei, Stefano, De Cecco, Mariolino, Deller, Jakob, Fornasier, Sonia, Fulle, Marco, Groussin, Olivier, Gutierrez, Pedro J., Guttler, Carsten, Hofmann, Marc, Hviid, Stubbe F., Jorda, Laurent, Knollenberg, J. Org, Kovacs, Gabor, Kramm, J. -Rainer, Kuhrt, Ekkehard, Kuppers, Michael, Lara, Luisa M., Lazzarin, Monica, Moreno, Jose J. Lopez, Marzari, Francesco, Naletto, Giampiero, Oklay, Nilda, Shi, Xian, Tubiana, Cecilia, and Vincent, Jean-Baptiste
- Abstract
Because of the diurnal thermal cycle and the irregular shape of the nucleus, gas outflow of comet 67P/Churyumov-Gerasimenko could be highly anisotropic as indicated by the colliminated dust jet structures on the sunlit side. Based on the OSIRIS imaging observations of the outgassing effect, a simple model of surface sublimation can be constructed by taking into account the dependence on the solar insolation. With preliminary information on the time variability of the global gas production rate, a sequence of gas coma models can be generated at different epochs before and after perihelion. We also investigate different patterns of dust particle dynamics under the influences of nuclear rotation and gas drag. From these considerations, a consistent picture of the spatial distribution of dusty materials across the surface of comet 67P as it moves around the perihelion can be developed. It is found that because of the redeposition of the ejected dust from the Southern hemisphere to the Northern hemisphere during the southern summer season the Hapi region could gain up to 0.4 m while the Wosret region would lose up to 1.8 m of dust mantle per orbit.
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- 2016
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9. Geomorphological mapping of comet 67P/Churyumov-Gerasimenko's Southern hemisphere
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Lee, Jui-Chi, Massironi, Matteo, Ip, Wing-Huen, Giacomini, Lorenza, Ferrari, Sabrina, Penasa, Luca, El-Maarry, Mohamed Ramy, Pajola, Maurizio, Lai, Ian-Lin, Lin, Zhong-Yi, Ferri, Francesca, Sierks, Holger, Barbieri, Cesare, Lamy, Philippe, Rodrigo, Rafael, Koschny, Detlef, Rickman, Hans, Keller, Horst Uwe, Agarwal, Jessica, A'Hearn, Michael F., Barucci, Maria Antonella, Bertaux, Jean-Loup, Bertini, Ivano, Cremonese, Gabriele, Da Deppo, Vania, Davidsson, Björn, Debei, Stefano, De Cecco, Mariolino, Deller, Jakob, Fornasier, Sonia, Fulle, Marco, Groussin, Olivier, Gutierrez, Pedro J., Guettler, Carsten, Hofmann, Marc, Hviid, Stubbe F., Jorda, Laurent, Knollenberg, Joerg, Kovacs, Gabor, Kramm, J. -Rainer, Kuehrt, Ekkehard, Kuppers, Michael, Lara, Luisa M., Lazzarin, Monica, Marzari, Francesco, Lopez Moreno, Jose J., Naletto, Giampiero, Oklay, Nilda, Shi, Xian, Thomas, Nicolas, Tubiana, Cecilia, Vincent, Jean-Baptiste, Lee, Jui-Chi, Massironi, Matteo, Ip, Wing-Huen, Giacomini, Lorenza, Ferrari, Sabrina, Penasa, Luca, El-Maarry, Mohamed Ramy, Pajola, Maurizio, Lai, Ian-Lin, Lin, Zhong-Yi, Ferri, Francesca, Sierks, Holger, Barbieri, Cesare, Lamy, Philippe, Rodrigo, Rafael, Koschny, Detlef, Rickman, Hans, Keller, Horst Uwe, Agarwal, Jessica, A'Hearn, Michael F., Barucci, Maria Antonella, Bertaux, Jean-Loup, Bertini, Ivano, Cremonese, Gabriele, Da Deppo, Vania, Davidsson, Björn, Debei, Stefano, De Cecco, Mariolino, Deller, Jakob, Fornasier, Sonia, Fulle, Marco, Groussin, Olivier, Gutierrez, Pedro J., Guettler, Carsten, Hofmann, Marc, Hviid, Stubbe F., Jorda, Laurent, Knollenberg, Joerg, Kovacs, Gabor, Kramm, J. -Rainer, Kuehrt, Ekkehard, Kuppers, Michael, Lara, Luisa M., Lazzarin, Monica, Marzari, Francesco, Lopez Moreno, Jose J., Naletto, Giampiero, Oklay, Nilda, Shi, Xian, Thomas, Nicolas, Tubiana, Cecilia, and Vincent, Jean-Baptiste
- Abstract
In 2015 May, the Southern hemisphere of comet 67P/Churyumov-Gerasimenko became visible by the OSIRIS cameras on-board the Rosetta spacecraft. The resolution was high enough to carry out a detailed analysis of the surface morphology, which is quite different from the Northern hemisphere. Previous works show that fine particle deposits are the most extensive geological unit in the Northern hemisphere. In contrast, the Southern hemisphere is dominated by outcropping consolidated terrain. In this work, we provide geomorphological maps of the Southern hemisphere with the distinction of both geological units and linear features. The geomorphological maps described in this study allow us to gain a better understanding of the processes shaping the comet nucleus and the distribution of primary structures such as fractures and strata.
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- 2016
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10. Gas outflow and dust transport of comet 67P/Churyumov–Gerasimenko
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Lai, Ian-Lin, primary, Ip, Wing-Huen, additional, Su, Cheng-Chin, additional, Wu, Jong-Shinn, additional, Lee, Jui-Chi, additional, Lin, Zhong-Yi, additional, Liao, Ying, additional, Thomas, Nicolas, additional, Sierks, Holger, additional, Barbieri, Cesare, additional, Lamy, Philippe, additional, Rodrigo, Rafael, additional, Koschny, Detlef, additional, Rickman, Hans, additional, Keller, Horst Uwe, additional, Agarwal, Jessica, additional, A’Hearn, Michael F., additional, Barucci, Maria Antonella, additional, Bertaux, Jean-Loup, additional, Bertini, Ivano, additional, Boudreault, Steven, additional, Cremonese, Gabriele, additional, Da Deppo, Vania, additional, Davidsson, Björn, additional, Debei, Stefano, additional, De Cecco, Mariolino, additional, Deller, Jakob, additional, Fornasier, Sonia, additional, Fulle, Marco, additional, Groussin, Olivier, additional, Gutiérrez, Pedro J., additional, Güttler, Carsten, additional, Hofmann, Marc, additional, Hviid, Stubbe F., additional, Jorda, Laurent, additional, Knollenberg, Jörg, additional, Kovacs, Gabor, additional, Kramm, J.-Rainer, additional, Kührt, Ekkehard, additional, Küppers, Michael, additional, Lara, Luisa M., additional, Lazzarin, Monica, additional, Lopez Moreno, Josè J., additional, Marzari, Francesco, additional, Naletto, Giampiero, additional, Oklay, Nilda, additional, Shi, Xian, additional, Tubiana, Cecilia, additional, and Vincent, Jean-Baptiste, additional
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- 2016
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11. Geomorphological mapping of comet 67P/Churyumov–Gerasimenko’s Southern hemisphere
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Lee, Jui-Chi, primary, Massironi, Matteo, additional, Ip, Wing-Huen, additional, Giacomini, Lorenza, additional, Ferrari, Sabrina, additional, Penasa, Luca, additional, El-Maarry, Mohamed Ramy, additional, Pajola, Maurizio, additional, Lai, Ian-Lin, additional, Lin, Zhong-Yi, additional, Ferri, Francesca, additional, Sierks, Holger, additional, Barbieri, Cesare, additional, Lamy, Philippe, additional, Rodrigo, Rafael, additional, Koschny, Detlef, additional, Rickman, Hans, additional, Keller, Horst Uwe, additional, Agarwal, Jessica, additional, A’Hearn, Michael F., additional, Barucci, Maria Antonella, additional, Bertaux, Jean-Loup, additional, Bertini, Ivano, additional, Cremonese, Gabriele, additional, Da Deppo, Vania, additional, Davidsson, Björn, additional, Debei, Stefano, additional, De Cecco, Mariolino, additional, Deller, Jakob, additional, Fornasier, Sonia, additional, Fulle, Marco, additional, Groussin, Olivier, additional, Gutiérrez, Pedro J., additional, Güttler, Carsten, additional, Hofmann, Marc, additional, Hviid, Stubbe F., additional, Jorda, Laurent, additional, Knollenberg, Jörg, additional, Kovacs, Gabor, additional, Kramm, J.-Rainer, additional, Kührt, Ekkehard, additional, Küppers, Michael, additional, Lara, Luisa M., additional, Lazzarin, Monica, additional, Marzari, Francesco, additional, Lopez Moreno, Josè J., additional, Naletto, Giampiero, additional, Oklay, Nilda, additional, Shi, Xian, additional, Thomas, Nicolas, additional, Tubiana, Cecilia, additional, and Vincent, Jean-Baptiste, additional
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- 2016
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12. Aswan site on comet 67P/Churyumov-Gerasimenko: Morphology, boulder evolution, and spectrophotometry
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Pajola, Maurizio, primary, Oklay, Nilda, additional, La Forgia, Fiorangela, additional, Giacomini, Lorenza, additional, Massironi, Matteo, additional, Bertini, Ivano, additional, El-Maarry, M. R., additional, Marzari, Francesco, additional, Preusker, Frank, additional, Scholten, Frank, additional, Höfner, Sebastian, additional, Lee, Jui-Chi, additional, Vincent, Jean-Baptiste, additional, Groussin, Olivier, additional, Naletto, Giampiero, additional, Lazzarin, Monica, additional, Barbieri, Cesare, additional, Sierks, Holger, additional, Lamy, Philippe, additional, Rodrigo, Rafael, additional, Koschny, Detlef, additional, Rickman, Hans, additional, Keller, Horst U., additional, Agarwal, Jessica, additional, A’Hearn, Michael F., additional, Barucci, Maria A., additional, Bertaux, Jean-Loup, additional, Cremonese, Gabriele, additional, Deppo, Vania Da, additional, Davidsson, Björn, additional, De Cecco, Mariolino, additional, Debei, Stefano, additional, Ferri, Francesca, additional, Fornasier, Sonia, additional, Fulle, Marco, additional, Güttler, Carsten, additional, Gutierrez, Pedro J., additional, Hviid, Stubbe F., additional, Ip, Wing-Huen, additional, Jorda, Laurent, additional, Knollenberg, Jörg, additional, Kramm, J.-Rainer, additional, Küppers, Michael, additional, Kürt, Ekkehard, additional, Lara, Luisa M., additional, Lin, Zhong-Yi, additional, Lopez Moreno, Jose J., additional, Magrin, Sara, additional, Michalik, Harald, additional, Mottola, Stefano, additional, Thomas, Nicholas, additional, and Tubiana, Cecilia, additional
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- 2016
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13. The southern hemisphere of 67P/Churyumov-Gerasimenko: Analysis of the preperihelion size-frequency distribution of boulders ≥7 m
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Pajola, Maurizio, primary, Lucchetti, Alice, additional, Vincent, Jean-Baptiste, additional, Oklay, Nilda, additional, El-Maarry, Mohamed R., additional, Bertini, Ivano, additional, Naletto, Giampiero, additional, Lazzarin, Monica, additional, Massironi, Matteo, additional, Sierks, Holger, additional, Barbieri, Cesare, additional, Lamy, Philippe, additional, Rodrigo, Rafael, additional, Koschny, Detlef, additional, Rickman, Hans, additional, Keller, Horst U., additional, Agarwal, Jessica, additional, A’Hearn, Michael F., additional, Barucci, Maria A., additional, Bertaux, Jean-Loup, additional, Boudreault, Steve, additional, Cremonese, Gabriele, additional, Deppo, Vania Da, additional, Davidsson, Björn, additional, Debei, Stefano, additional, De Cecco, Mariolino, additional, Deller, Jakob, additional, Fornasier, Sonia, additional, Fulle, Marco, additional, Gicquel, Adeline, additional, Groussin, Olivier, additional, Gutierrez, Pedro J., additional, Güttler, Carsten, additional, Hofmann, Marc, additional, Höfner, Sebastian, additional, Hviid, Stubbe F., additional, Ip, Wing-Huen, additional, Jorda, Laurent, additional, Knollenberg, Jörg, additional, Kramm, J.-Rainer, additional, Kührt, Ekkehard, additional, Küppers, Michael, additional, La Forgia, Fiorangela, additional, Lara, Luisa M., additional, Lee, Jui-Chi, additional, Lin, Zhong-Yi, additional, Lopez Moreno, Jose J., additional, Marzari, Francesco, additional, Michalik, Harald, additional, Mottola, Stefano, additional, Preusker, Frank, additional, Scholten, Frank, additional, Thomas, Nicholas, additional, Toth, Imre, additional, and Tubiana, Cecilia, additional
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- 2016
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14. On the nucleus structure and activity of comet 67P/Churyumov-Gerasimenko
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Sierks, Holger, Barbieri, Cesare, Lamy, Philippe L., Rodrigo, Rafael, Koschny, Detlef, Rickman, Hans, Keller, Horst Uwe, Agarwal, Jessica, A'Hearn, Michael F., Angrilli, Francesco, Auger, Anne-Therese, Barucci, M. Antonella, Bertaux, Jean-Loup, Bertini, Ivano, Besse, Sebastien, Bodewits, Dennis, Capanna, Claire, Cremonese, Gabriele, Da Deppo, Vania, Davidsson, Bjoern, Debei, Stefano, De Cecco, Mariolino, Ferri, Francesca, Fornasier, Sonia, Fulle, Marco, Gaskell, Robert, Giacomini, Lorenza, Groussin, Olivier, Gutierrez-Marques, Pablo, Gutiuerrez, Pedro J., Guettler, Carsten, Hoekzema, Nick, Hviid, Stubbe F., Ip, Wing-Huen, Jorda, Laurent, Knollenberg, Joerg, Kovacs, Gabor, Kramm, J. Rainer, Kuehrt, Ekkehard, Kueppers, Michael, La Forgia, Fiorangela, Lara, Luisa M., Lazzarin, Monica, Leyrat, Cedric, Moreno, Jose J. Lopez, Magrin, Sara, Marchi, Simone, Marzari, Francesco, Massironi, Matteo, Michalik, Harald, Moissl, Richard, Mottola, Stefano, Naletto, Giampiero, Oklay, Nilda, Pajola, Maurizio, Pertile, Marco, Preusker, Frank, Sabau, Lola, Scholten, Frank, Snodgrass, Colin, Thomas, Nicolas, Tubiana, Cecilia, Vincent, Jean-Baptiste, Wenzel, Klaus-Peter, Zaccariotto, Mirco, Paetzold, Martin, Sierks, Holger, Barbieri, Cesare, Lamy, Philippe L., Rodrigo, Rafael, Koschny, Detlef, Rickman, Hans, Keller, Horst Uwe, Agarwal, Jessica, A'Hearn, Michael F., Angrilli, Francesco, Auger, Anne-Therese, Barucci, M. Antonella, Bertaux, Jean-Loup, Bertini, Ivano, Besse, Sebastien, Bodewits, Dennis, Capanna, Claire, Cremonese, Gabriele, Da Deppo, Vania, Davidsson, Bjoern, Debei, Stefano, De Cecco, Mariolino, Ferri, Francesca, Fornasier, Sonia, Fulle, Marco, Gaskell, Robert, Giacomini, Lorenza, Groussin, Olivier, Gutierrez-Marques, Pablo, Gutiuerrez, Pedro J., Guettler, Carsten, Hoekzema, Nick, Hviid, Stubbe F., Ip, Wing-Huen, Jorda, Laurent, Knollenberg, Joerg, Kovacs, Gabor, Kramm, J. Rainer, Kuehrt, Ekkehard, Kueppers, Michael, La Forgia, Fiorangela, Lara, Luisa M., Lazzarin, Monica, Leyrat, Cedric, Moreno, Jose J. Lopez, Magrin, Sara, Marchi, Simone, Marzari, Francesco, Massironi, Matteo, Michalik, Harald, Moissl, Richard, Mottola, Stefano, Naletto, Giampiero, Oklay, Nilda, Pajola, Maurizio, Pertile, Marco, Preusker, Frank, Sabau, Lola, Scholten, Frank, Snodgrass, Colin, Thomas, Nicolas, Tubiana, Cecilia, Vincent, Jean-Baptiste, Wenzel, Klaus-Peter, Zaccariotto, Mirco, and Paetzold, Martin
- Abstract
Images from the OSIRIS scientific imaging system onboard Rosetta show that the nucleus of 67P/Churyumov-Gerasimenko consists of two lobes connected by a short neck. The nucleus has a bulk density less than half that of water. Activity at a distance from the Sun of >3 astronomical units is predominantly from the neck, where jets have been seen consistently. The nucleus rotates about the principal axis of momentum. The surface morphology suggests that the removal of larger volumes of material, possibly via explosive release of subsurface pressure or via creation of overhangs by sublimation, may be a major mass loss process. The shape raises the question of whether the two lobes represent a contact binary formed 4.5 billion years ago, or a single body where a gap has evolved via mass loss.
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- 2015
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15. The morphological diversity of comet 67P/Churyumov-Gerasimenko
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Thomas, Nicolas, Sierks, Holger, Barbieri, Cesare, Lamy, Philippe L., Rodrigo, Rafael, Rickman, Hans, Koschny, Detlef, Keller, Horst Uwe, Agarwal, Jessica, A'Hearn, Michael F., Angrilli, Francesco, Auger, Anne-Therese, Barucci, M. Antonella, Bertaux, Jean-Loup, Bertini, Ivano, Besse, Sebastien, Bodewits, Dennis, Cremonese, Gabriele, Da Deppo, Vania, Davidsson, Björn, De Cecco, Mariolino, Debei, Stefano, El-Maarry, Mohamed Ramy, Ferri, Francesca, Fornasier, Sonia, Fulle, Marco, Giacomini, Lorenza, Groussin, Olivier, Gutierrez, Pedro J., Guettler, Carsten, Hviid, Stubbe F., Ip, Wing-Huen, Jorda, Laurent, Knollenberg, Joerg, Kramm, J. -Rainer, Kuehrt, Ekkehard, Kueppers, Michael, La Forgia, Fiorangela, Lara, Luisa M., Lazzarin, Monica, Moreno, Jose J. Lopez, Magrin, Sara, Marchi, Simone, Marzari, Francesco, Massironi, Matteo, Michalik, Harald, Moissl, Richard, Mottola, Stefano, Naletto, Giampiero, Oklay, Nilda, Pajola, Maurizio, Pommerol, Antoine, Preusker, Frank, Sabau, Lola, Scholten, Frank, Snodgrass, Colin, Tubiana, Cecilia, Vincent, Jean-Baptiste, Wenzel, Klaus-Peter, Thomas, Nicolas, Sierks, Holger, Barbieri, Cesare, Lamy, Philippe L., Rodrigo, Rafael, Rickman, Hans, Koschny, Detlef, Keller, Horst Uwe, Agarwal, Jessica, A'Hearn, Michael F., Angrilli, Francesco, Auger, Anne-Therese, Barucci, M. Antonella, Bertaux, Jean-Loup, Bertini, Ivano, Besse, Sebastien, Bodewits, Dennis, Cremonese, Gabriele, Da Deppo, Vania, Davidsson, Björn, De Cecco, Mariolino, Debei, Stefano, El-Maarry, Mohamed Ramy, Ferri, Francesca, Fornasier, Sonia, Fulle, Marco, Giacomini, Lorenza, Groussin, Olivier, Gutierrez, Pedro J., Guettler, Carsten, Hviid, Stubbe F., Ip, Wing-Huen, Jorda, Laurent, Knollenberg, Joerg, Kramm, J. -Rainer, Kuehrt, Ekkehard, Kueppers, Michael, La Forgia, Fiorangela, Lara, Luisa M., Lazzarin, Monica, Moreno, Jose J. Lopez, Magrin, Sara, Marchi, Simone, Marzari, Francesco, Massironi, Matteo, Michalik, Harald, Moissl, Richard, Mottola, Stefano, Naletto, Giampiero, Oklay, Nilda, Pajola, Maurizio, Pommerol, Antoine, Preusker, Frank, Sabau, Lola, Scholten, Frank, Snodgrass, Colin, Tubiana, Cecilia, Vincent, Jean-Baptiste, and Wenzel, Klaus-Peter
- Abstract
Images of comet 67P/Churyumov-Gerasimenko acquired by the OSIRIS (Optical, Spectroscopic and Infrared Remote Imaging System) imaging system onboard the European Space Agency's Rosetta spacecraft at scales of better than 0.8 meter per pixel show a wide variety of different structures and textures. The data show the importance of airfall, surface dust transport, mass wasting, and insolation weathering for cometary surface evolution, and they offer some support for subsurface fluidization models and mass loss through the ejection of large chunks of material.
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- 2015
- Full Text
- View/download PDF
16. Size-frequency distribution of boulders >= 7 m on comet 67P/Churyumov-Gerasimenko
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Pajola, Maurizio, Vincent, Jean-Baptiste, Guettler, Carsten, Lee, Jui-Chi, Bertini, Ivano, Massironi, Matteo, Simioni, Emanuele, Marzari, Francesco, Giacomini, Lorenza, Lucchetti, Alice, Barbieri, Cesare, Cremonese, Gabriele, Naletto, Giampiero, Pommerol, Antoine, El-Maarry, Mohamed R., Besse, Sebastien, Kueppers, Michael, La Forgia, Fiorangela, Lazzarin, Monica, Thomas, Nicholas, Auger, Anne-Therese, Sierks, Holger, Lamy, Philippe, Rodrigo, Rafael, Koschny, Detlef, Rickman, Hans, Keller, Horst U., Agarwal, Jessica, A'Hearn, Michael F., Barucci, Maria A., Bertaux, Jean-Loup, Da Deppo, Vania, Davidsson, Björn, De Cecco, Mariolino, Debei, Stefano, Ferri, Francesca, Fornasier, Sonia, Fulle, Marco, Groussin, Olivier, Gutierrez, Pedro J., Hviid, Stubbe F., Ip, Wing-Huen, Jorda, Laurent, Knollenberg, Joerg, Kramm, J. -Rainer, Kuert, Ekkehard, Lara, Luisa M., Lin, Zhong-Yi, Lopez Moreno, Jose J., Magrin, Sara, Marchi, Simone, Michalik, Harald, Moissl, Richard, Mottola, Stefano, Oklay, Nilda, Preusker, Frank, Scholten, Frank, Tubiana, Cecilia, Pajola, Maurizio, Vincent, Jean-Baptiste, Guettler, Carsten, Lee, Jui-Chi, Bertini, Ivano, Massironi, Matteo, Simioni, Emanuele, Marzari, Francesco, Giacomini, Lorenza, Lucchetti, Alice, Barbieri, Cesare, Cremonese, Gabriele, Naletto, Giampiero, Pommerol, Antoine, El-Maarry, Mohamed R., Besse, Sebastien, Kueppers, Michael, La Forgia, Fiorangela, Lazzarin, Monica, Thomas, Nicholas, Auger, Anne-Therese, Sierks, Holger, Lamy, Philippe, Rodrigo, Rafael, Koschny, Detlef, Rickman, Hans, Keller, Horst U., Agarwal, Jessica, A'Hearn, Michael F., Barucci, Maria A., Bertaux, Jean-Loup, Da Deppo, Vania, Davidsson, Björn, De Cecco, Mariolino, Debei, Stefano, Ferri, Francesca, Fornasier, Sonia, Fulle, Marco, Groussin, Olivier, Gutierrez, Pedro J., Hviid, Stubbe F., Ip, Wing-Huen, Jorda, Laurent, Knollenberg, Joerg, Kramm, J. -Rainer, Kuert, Ekkehard, Lara, Luisa M., Lin, Zhong-Yi, Lopez Moreno, Jose J., Magrin, Sara, Marchi, Simone, Michalik, Harald, Moissl, Richard, Mottola, Stefano, Oklay, Nilda, Preusker, Frank, Scholten, Frank, and Tubiana, Cecilia
- Abstract
Aims. We derive for the first time the size-frequency distribution of boulders on a comet, 67P/Churyumov-Gerasimenko (67P), computed from the images taken by the Rosetta/OSIRIS imaging system. We highlight the possible physical processes that lead to these boulder size distributions. Methods. We used images acquired by the OSIRIS Narrow Angle Camera, NAC. on 5 and 6 August 2014. The scale of these images (2.44-2.03 m/px) is such that boulders >= 7 m can be identified and manually extracted from the datasets with the software ArcGIS. We derived both global and localized size-frequency distributions. The three-pixel sampling detection, coupled with the favorable shadowine of the surface (observation phase angle ranging from 48 to 53), enables unequivocally detecting boulders scattered all over the illuminated side of 67P. Results. We identify 3546 boulders larger than 7 m on the imaged surface (36.4 km(2)), with a global number density of nearly 100/km(2) and a cumulative size-frequency distribution represented by a power-law with index of -3.6 +0.2/-0.3. The two lobes of 67P appear to have slightly different distributions, with an index of -3.5 +0.2/-0.3 for the main lobe (body) and -4.0 +0.31-0.2 for the small lobe (head). The steeper distribution of the small lobe might be due to a more pervasive fracturing. The difference of the distribution for the connecting region (neck) is much more significant, with an index value of -2.2 +0.2/-0.2. We propose that the boulder field located in the neck area is the result of blocks falling from the contiguous Hathor cliff. The lower slope of the size-frequency distribution we see today in the neck area might be due to the concurrent processes acting on the smallest boulders, such as i) disintegration or fragmentation and vanishing through sublimation; ii) uplifting by gas drag and consequent redistribution; and iii) burial beneath a debris blanket. We also derived the cumulative size-frequency distribution per km(2) of loca
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- 2015
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- View/download PDF
17. Size-frequency distribution of boulders ≥7 m on comet 67P/Churyumov-Gerasimenko
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Pajola, Maurizio, primary, Vincent, Jean-Baptiste, additional, Güttler, Carsten, additional, Lee, Jui-Chi, additional, Bertini, Ivano, additional, Massironi, Matteo, additional, Simioni, Emanuele, additional, Marzari, Francesco, additional, Giacomini, Lorenza, additional, Lucchetti, Alice, additional, Barbieri, Cesare, additional, Cremonese, Gabriele, additional, Naletto, Giampiero, additional, Pommerol, Antoine, additional, El-Maarry, Mohamed R., additional, Besse, Sébastien, additional, Küppers, Michael, additional, La Forgia, Fiorangela, additional, Lazzarin, Monica, additional, Thomas, Nicholas, additional, Auger, Anne-Thérèse, additional, Sierks, Holger, additional, Lamy, Philippe, additional, Rodrigo, Rafael, additional, Koschny, Detlef, additional, Rickman, Hans, additional, Keller, Horst U., additional, Agarwal, Jessica, additional, A’Hearn, Michael F., additional, Barucci, Maria A., additional, Bertaux, Jean-Loup, additional, Deppo, Vania Da, additional, Davidsson, Björn, additional, De Cecco, Mariolino, additional, Debei, Stefano, additional, Ferri, Francesca, additional, Fornasier, Sonia, additional, Fulle, Marco, additional, Groussin, Olivier, additional, Gutierrez, Pedro J., additional, Hviid, Stubbe F., additional, Ip, Wing-Huen, additional, Jorda, Laurent, additional, Knollenberg, Jörg, additional, Kramm, J.-Rainer, additional, Kürt, Ekkehard, additional, Lara, Luisa M., additional, Lin, Zhong-Yi, additional, Moreno, Jose J. Lopez, additional, Magrin, Sara, additional, Marchi, Simone, additional, Michalik, Harald, additional, Moissl, Richard, additional, Mottola, Stefano, additional, Oklay, Nilda, additional, Preusker, Frank, additional, Scholten, Frank, additional, and Tubiana, Cecilia, additional
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- 2015
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18. The morphological diversity of comet 67P/Churyumov-Gerasimenko
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Thomas, Nicolas, primary, Sierks, Holger, additional, Barbieri, Cesare, additional, Lamy, Philippe L., additional, Rodrigo, Rafael, additional, Rickman, Hans, additional, Koschny, Detlef, additional, Keller, Horst Uwe, additional, Agarwal, Jessica, additional, A'Hearn, Michael F., additional, Angrilli, Francesco, additional, Auger, Anne-Therese, additional, Barucci, M. Antonella, additional, Bertaux, Jean-Loup, additional, Bertini, Ivano, additional, Besse, Sebastien, additional, Bodewits, Dennis, additional, Cremonese, Gabriele, additional, Da Deppo, Vania, additional, Davidsson, Björn, additional, De Cecco, Mariolino, additional, Debei, Stefano, additional, El-Maarry, Mohamed Ramy, additional, Ferri, Francesca, additional, Fornasier, Sonia, additional, Fulle, Marco, additional, Giacomini, Lorenza, additional, Groussin, Olivier, additional, Gutierrez, Pedro J., additional, Güttler, Carsten, additional, Hviid, Stubbe F., additional, Ip, Wing-Huen, additional, Jorda, Laurent, additional, Knollenberg, Jörg, additional, Kramm, J.-Rainer, additional, Kührt, Ekkehard, additional, Küppers, Michael, additional, La Forgia, Fiorangela, additional, Lara, Luisa M., additional, Lazzarin, Monica, additional, Moreno, Josè J. Lopez, additional, Magrin, Sara, additional, Marchi, Simone, additional, Marzari, Francesco, additional, Massironi, Matteo, additional, Michalik, Harald, additional, Moissl, Richard, additional, Mottola, Stefano, additional, Naletto, Giampiero, additional, Oklay, Nilda, additional, Pajola, Maurizio, additional, Pommerol, Antoine, additional, Preusker, Frank, additional, Sabau, Lola, additional, Scholten, Frank, additional, Snodgrass, Colin, additional, Tubiana, Cecilia, additional, Vincent, Jean-Baptiste, additional, and Wenzel, Klaus-Peter, additional
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- 2015
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19. On the nucleus structure and activity of comet 67P/Churyumov-Gerasimenko
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Sierks, Holger, primary, Barbieri, Cesare, additional, Lamy, Philippe L., additional, Rodrigo, Rafael, additional, Koschny, Detlef, additional, Rickman, Hans, additional, Keller, Horst Uwe, additional, Agarwal, Jessica, additional, A’Hearn, Michael F., additional, Angrilli, Francesco, additional, Auger, Anne-Therese, additional, Barucci, M. Antonella, additional, Bertaux, Jean-Loup, additional, Bertini, Ivano, additional, Besse, Sebastien, additional, Bodewits, Dennis, additional, Capanna, Claire, additional, Cremonese, Gabriele, additional, Da Deppo, Vania, additional, Davidsson, Björn, additional, Debei, Stefano, additional, De Cecco, Mariolino, additional, Ferri, Francesca, additional, Fornasier, Sonia, additional, Fulle, Marco, additional, Gaskell, Robert, additional, Giacomini, Lorenza, additional, Groussin, Olivier, additional, Gutierrez-Marques, Pablo, additional, Gutiérrez, Pedro J., additional, Güttler, Carsten, additional, Hoekzema, Nick, additional, Hviid, Stubbe F., additional, Ip, Wing-Huen, additional, Jorda, Laurent, additional, Knollenberg, Jörg, additional, Kovacs, Gabor, additional, Kramm, J. Rainer, additional, Kührt, Ekkehard, additional, Küppers, Michael, additional, La Forgia, Fiorangela, additional, Lara, Luisa M., additional, Lazzarin, Monica, additional, Leyrat, Cédric, additional, Lopez Moreno, Josè J., additional, Magrin, Sara, additional, Marchi, Simone, additional, Marzari, Francesco, additional, Massironi, Matteo, additional, Michalik, Harald, additional, Moissl, Richard, additional, Mottola, Stefano, additional, Naletto, Giampiero, additional, Oklay, Nilda, additional, Pajola, Maurizio, additional, Pertile, Marco, additional, Preusker, Frank, additional, Sabau, Lola, additional, Scholten, Frank, additional, Snodgrass, Colin, additional, Thomas, Nicolas, additional, Tubiana, Cecilia, additional, Vincent, Jean-Baptiste, additional, Wenzel, Klaus-Peter, additional, Zaccariotto, Mirco, additional, and Pätzold, Martin, additional
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- 2015
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20. Imaging Technique of the DISR Camera on the Huygens Lander
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Kramm, J. Rainer, primary, Keller, Horst Uwe, additional, Bredthauer, Richard, additional, and Tomasko, Martin, additional
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21. Size-frequency distribution of boulders ≥7 m on comet 67P/Churyumov-Gerasimenko
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Da Deppo, Vania, Ip, Wing-Huen, Marzari, Francesco, Scholten, Frank, Preusker, Frank, Besse, Sebastien, Guettler, Carsten, Mottola, Stefano, Barucci, Maria A., Davidsson, Bjoern, De Cecco, Mariolino, Kuert, Ekkehard, La Forgia, Fiorangela, Lopez Moreno, Jose J., Fornasier, Sonia, Hviid, Stubbe F., Cremonese, Gabriele, Lee, Jui-Chi, Bertini, Ivano, Kueppers, Michael, Lazzarin, Monica, Gutierrez, Pedro J., Ferri, Francesca, Lamy, Philippe, Thomas, Nicholas, Lara, Luisa M., Massironi, Matteo, Koschny, Detlef, Auger, Anne-Therese, Vincent, Jean-Baptiste, Knollenberg, Joerg, Debei, Stefano, Groussin, Olivier, Fulle, Marco, Jorda, Laurent, Magrin, Sara, Oklay, Nilda, Bertaux, Jean-Loup, Sierks, Holger, Elmaarry, Mohamed Ramy, Kramm, J. Rainer, Barbieri, Cesare, Keller, Horst U., A'Hearn, Michael F., Pajola, Maurizio, Marchi, Simone, Simioni, Emanuele, Giacomini, Lorenza, Pommerol, Antoine, Tubiana, Cecilia, Lucchetti, Alice, Rickman, Hans, Naletto, Giampiero, Lin, Zhong-Yi, Agarwal, Jessica, Moissl, Richard, Rodrigo, Rafael, and Michalik, Harald
- Subjects
13. Climate action ,530 Physics ,500 Science - Abstract
Aims. We derive for the first time the size-frequency distribution of boulders on a comet, 67P/Churyumov-Gerasimenko (67P), computed from the images taken by the Rosetta/OSIRIS imaging system. We highlight the possible physical processes that lead to these boulder size distributions. Methods. We used images acquired by the OSIRIS Narrow Angle Camera, NAC, on 5 and 6 August 2014. The scale of these images (2.44−2.03 m/px) is such that boulders ≥7 m can be identified and manually extracted from the datasets with the software ArcGIS. We derived both global and localized size-frequency distributions. The three-pixel sampling detection, coupled with the favorable shadowing of the surface (observation phase angle ranging from 48° to 53°), enables unequivocally detecting boulders scattered all over the illuminated side of 67P. Results. We identify 3546 boulders larger than 7 m on the imaged surface (36.4 km2), with a global number density of nearly 100/km2 and a cumulative size-frequency distribution represented by a power-law with index of −3.6 +0.2/−0.3. The two lobes of 67P appear to have slightly different distributions, with an index of −3.5 +0.2/−0.3 for the main lobe (body) and −4.0 +0.3/−0.2 for the small lobe (head). The steeper distribution of the small lobe might be due to a more pervasive fracturing. The difference of the distribution for the connecting region (neck) is much more significant, with an index value of −2.2 +0.2/−0.2. We propose that the boulder field located in the neck area is the result of blocks falling from the contiguous Hathor cliff. The lower slope of the size-frequency distribution we see today in the neck area might be due to the concurrent processes acting on the smallest boulders, such as i) disintegration or fragmentation and vanishing through sublimation; ii) uplifting by gas drag and consequent redistribution; and iii) burial beneath a debris blanket. We also derived the cumulative size-frequency distribution per km2 of localized areas on 67P. By comparing the cumulative size-frequency distributions of similar geomorphological settings, we derived similar power-law index values. This suggests that despite the selected locations on different and often opposite sides of the comet, similar sublimation or activity processes, pit formation or collapses, as well as thermal stresses or fracturing events occurred on multiple areas of the comet, shaping its surface into the appearance we see today.
22. The morphological diversity of comet 67P/Churyumov-Gerasimenko
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De Cecco, Mariolino, Besse, Sebastien, Mottola, Stefano, Koschny, Detlef, Barucci, M. Antonella, Davidsson, Bjoern, Knollenberg, Joerg, Sabau, Lola, Rickman, Hans, A'Hearn, Michael F., Rodrigo, Rafael, Oklay, Nilda, Angrilli, Francesco, Tubiana, Cecilia, Auger, Anne-Therese, Bertaux, Jean-Loup, Pommerol, Antoine, Naletto, Giampiero, Fornasier, Sonia, Kramm, J. Rainer, Moreno, Jose J. Lopez, Magrin, Sara, Marzari, Francesco, Debei, Stefano, Lazzarin, Monica, Gutierrez, Pedro J., Barbieri, Cesare, Agarwal, Jessica, Elmaarry, Mohamed Ramy, Groussin, Olivier, Fulle, Marco, Thomas, Nicolas, Keller, Horst Uwe, Cremonese, Gabriele, Massironi, Matteo, La Forgia, Fiorangela, Snodgrass, Colin, Preusker, Frank, Marchi, Simone, Ip, Wing-Huen, Kueppers, Michael, Giacomini, Lorenza, Vincent, Jean-Baptiste, Jorda, Laurent, Guettler, Carsten, Ferri, Francesca, Hviid, Stubbe F., Michalik, Harald, Moissl, Richard, Pajola, Maurizio, Lamy, Philippe L., Wenzel, Klaus-Peter, Lara, Luisa M., Bertini, Ivano, Bodewits, Dennis, Sierks, Holger, Scholten, Frank, Kuehrt, Ekkehard, and Da Deppo, Vania
- Subjects
13. Climate action ,530 Physics - Abstract
Images of comet 67P/Churyumov-Gerasimenko acquired by the OSIRIS (Optical, Spectroscopic and Infrared Remote Imaging System) imaging system onboard the European Space Agency's Rosetta spacecraft at scales of better than 0.8 meter per pixel show a wide variety of different structures and textures. The data show the importance of airfall, surface dust transport, mass wasting, and insolation weathering for cometary surface evolution, and they offer some support for subsurface fluidization models and mass loss through the ejection of large chunks of material.
23. The southern hemisphere of 67P/Churyumov-Gerasimenko: Analysis of the preperihelion size-frequency distribution of boulders ≥7 m
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La Forgia, Fiorangela, Hofmann, Marc, Fulle, Marco, Keller, Horst U., Toth, Imre, Agarwal, Jessica, Groussin, Olivier, Lopez Moreno, Jose J., De Cecco, Mariolino, Michalik, Harald, Gutierrez, Pedro J., Höfner, Sebastian, Vincent, Jean-Baptiste, Gicquel, Adeline, Naletto, Giampiero, Fornasier, Sonia, Deppo, Vania Da, Rickman, Hans, Elmaarry, Mohamed Ramy, Koschny, Detlef, Massironi, Matteo, Barucci, Maria A., Thomas, Nicolas, Kramm, J.-Rainer, Scholten, Frank, Bertaux, Jean-Loup, Lara, Luisa M., Lin, Zhong-Yi, Kührt, Ekkehard, Bertini, Ivano, Lamy, Philippe, Mottola, Stefano, Sierks, Holger, Lazzarin, Monica, Lee, Jui-Chi, Oklay, Nilda, Jorda, Laurent, Hviid, Stubbe F., Cremonese, Gabriele, Marzari, Francesco, Debei, Stefano, Pajola, Maurizio, Lucchetti, Alice, Davidsson, Björn, Tubiana, Cecilia, Küppers, Michael, Preusker, Frank, Ip, Wing-Huen, Güttler, Carsten, Boudreault, Steve, Rodrigo, Rafael, Barbieri, Cesare, Knollenberg, Jörg, A’Hearn, Michael F., and Deller, Jakob
- Subjects
13. Climate action ,530 Physics ,520 Astronomy ,620 Engineering - Abstract
Aims. We calculate the size-frequency distribution of the boulders on the southern hemisphere of comet 67P Churyumov-Gerasimenko (67P), which was in shadow before the end of April 2015. We compare the new results with those derived from the northern hemisphere and equatorial regions of 67P, highlighting the possible physical processes that lead to these boulder size distributions. Methods. We used images acquired by the OSIRIS Narrow Angle Camera (NAC) on 2 May 2015 at a distance of 125 km from the nucleus. The scale of this dataset is 2.3 m/px; the high resolution of the images, coupled with the favorable observation phase angle of 62 degrees, provided the possibility to unambiguously identify boulders ≥ 7 m on the surface of 67P and to manually extract them with the software ArcGIS. We derived the size-frequency distribution of the illuminated southern hemisphere. Results. We found a power-law index of -3.6 + 0.2 for the boulders on the southern hemisphere with a diameter range of 7-35 m. The power-law index is equal to the one previously found on northern and equatorial regions of 67P, suggesting that similar boulder formation processes occur in both hemispheres. The power-law index is related to gravitational events triggered by sublimation and/or thermal fracturing causing regressive erosion. In addition, the presence of a larger number of boulders per km² in the southern hemisphere, which is a factor of 3 higher with respect to the northern hemisphere, suggests that the southernmost terrains of 67P are affected by a stronger thermal fracturing and sublimating activity, hence possibly causing larger regressive erosion and gravitational events.
24. Cometary science. The morphological diversity of comet 67P/Churyumov-Gerasimenko.
- Author
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Thomas N, Sierks H, Barbieri C, Lamy PL, Rodrigo R, Rickman H, Koschny D, Keller HU, Agarwal J, A'Hearn MF, Angrilli F, Auger AT, Barucci MA, Bertaux JL, Bertini I, Besse S, Bodewits D, Cremonese G, Da Deppo V, Davidsson B, De Cecco M, Debei S, El-Maarry MR, Ferri F, Fornasier S, Fulle M, Giacomini L, Groussin O, Gutierrez PJ, Güttler C, Hviid SF, Ip WH, Jorda L, Knollenberg J, Kramm JR, Kührt E, Küppers M, La Forgia F, Lara LM, Lazzarin M, Lopez Moreno JJ, 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 JB, and Wenzel KP
- Abstract
Images of comet 67P/Churyumov-Gerasimenko acquired by the OSIRIS (Optical, Spectroscopic and Infrared Remote Imaging System) imaging system onboard the European Space Agency's Rosetta spacecraft at scales of better than 0.8 meter per pixel show a wide variety of different structures and textures. The data show the importance of airfall, surface dust transport, mass wasting, and insolation weathering for cometary surface evolution, and they offer some support for subsurface fluidization models and mass loss through the ejection of large chunks of material., (Copyright © 2015, American Association for the Advancement of Science.)
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- 2015
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- View/download PDF
25. Cometary science. On the nucleus structure and activity of comet 67P/Churyumov-Gerasimenko.
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Sierks H, Barbieri C, Lamy PL, Rodrigo R, Koschny D, Rickman H, Keller HU, Agarwal J, A'Hearn MF, Angrilli F, Auger AT, Barucci MA, Bertaux JL, 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 PJ, Güttler C, Hoekzema N, Hviid SF, Ip WH, Jorda L, Knollenberg J, Kovacs G, Kramm JR, Kührt E, Küppers M, La Forgia F, Lara LM, Lazzarin M, Leyrat C, Lopez Moreno JJ, 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 JB, Wenzel KP, Zaccariotto M, and Pätzold M
- Abstract
Images from the OSIRIS scientific imaging system onboard Rosetta show that the nucleus of 67P/Churyumov-Gerasimenko consists of two lobes connected by a short neck. The nucleus has a bulk density less than half that of water. Activity at a distance from the Sun of >3 astronomical units is predominantly from the neck, where jets have been seen consistently. The nucleus rotates about the principal axis of momentum. The surface morphology suggests that the removal of larger volumes of material, possibly via explosive release of subsurface pressure or via creation of overhangs by sublimation, may be a major mass loss process. The shape raises the question of whether the two lobes represent a contact binary formed 4.5 billion years ago, or a single body where a gap has evolved via mass loss., (Copyright © 2015, American Association for the Advancement of Science.)
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- 2015
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