OSIRIS observations of meter-sized exposures of H2O ice at the surface of 67P/Churyumov-Gerasimenko and interpretation using laboratory experiments

被引：94

作者：

Pommerol, A. ^{[1
]}

Thomas, N. ^{[1
]}

El-Maarry, M. R. ^{[1
]}

Pajola, M. ^{[2
]}

Groussin, O. ^{[3
]}

Auger, A. -T. ^{[3
]}

Oklay, N. ^{[4
]}

Fornasier, S. ^{[5
]}

Feller, C. ^{[5
]}

Davidsson, B. ^{[6
]}

Gracia-Berna, A. ^{[1
]}

Jost, B. ^{[1
]}

Marschall, R. ^{[1
]}

Poch, O. ^{[1
]}

Barucci, M. A. ^{[5
]}

Bertaux, J. -L. ^{[7
]}

La Forgia, F. ^{[8
]}

Keller, H. U. ^{[9
,10
]}

Kuehrt, E. ^{[9
]}

Lowry, S. C. ^{[11
]}

Mottola, S. ^{[9
]}

Naletto, G. ^{[2
,12
,13
]}

Sierks, H. ^{[4
]}

Barbieri, C. ^{[8
]}

Lamy, P. L. ^{[3
]}

Rodrigo, R. ^{[14
,15
]}

Koschny, D. ^{[16
]}

Rickman, H. ^{[6
,17
]}

Agarwal, J. ^{[4
]}

A'Hearn, M. F. ^{[18
]}

Bertini, I. ^{[2
]}

Boudreault, S. ^{[4
]}

Cremonese, G. ^{[19
]}

Da Deppo, V. ^{[13
]}

De Cecco, M. ^{[20
]}

Debei, S. ^{[21
]}

Guettler, C. ^{[4
]}

Fulle, M. ^{[22
]}

Gutierrez, P. J. ^{[22
]}

Hviid, S. F. ^{[9
]}

Ip, W. -H. ^{[24
]}

Jorda, L. ^{[3
]}

Knollenberg, J. ^{[9
]}

Kovacs, G. ^{[4
]}

Kramm, J. -R. ^{[4
]}

Kueppers, E. ^{[25
]}

Lara, L. ^{[23
]}

Lazzarin, M. ^{[8
]}

Lopez Moreno, J. L. ^{[23
]}

Marzari, F. ^{[8
]}

机构：

[1] Univ Bern, Inst Phys, CH-3012 Bern, Switzerland

[2] Univ Padua, Ctr Ateneo Studi & Attivita Spaziali, Giuseppe Colombo CISAS, I-35131 Padua, Italy

[3] Aix Marseille Univ, CNRS, UMR 7326, LAM, F-13388 Marseille, France

[4] Max Planck Inst Sonnensyst Forsch, D-37077 Gottingen, Germany

[5] Univ Paris Diderot, Univ Paris 06, CNRS, LESIA,Observ Paris, F-92195 Meudon, France

[6] Uppsala Univ, Dept Phys & Astron, S-75120 Uppsala, Sweden

[7] CNRS UVSQ IPSL, LATMOS, F-78280 Guyancourt, France

[8] Univ Padua, Dept Phys & Astron, I-35122 Padua, Italy

[9] Deutsch Zentrum Luft & Raumfahrt DLR, Inst Planetenforsch, D-12489 Berlin, Germany

[10] Tech Univ Carolo Wilhelmina Braunschweig, IGEP, D-38106 Braunschweig, Germany

[11] Univ Kent, Sch Phys Sci, Canterbury CT2 7NZ, Kent, England

[12] Univ Padua, Dept Informat Engn, I-35131 Padua, Italy

[13] CNR IFN UOS Padova LUXOR, I-35131 Padua, Italy

[14] Int Space Sci Inst, CH-3012 Bern, Switzerland

[15] CSIC INTA, Ctr Astrobiol, Madrid 28850, Spain

[16] European Space Agcy, Sci Support Off, NL-2201 Noordwijk, Netherlands

[17] PAS Space Res Ctr, PL-00716 Warsaw, Poland

[18] Univ Maryland, Dept Astron, College Pk, MD 20742 USA

[19] INAF Osservatorio Astron, I-35122 Padua, Italy

[20] Univ Trent, I-38100 Trento, Italy

[21] Univ Padua, Dept Ind Engn, I-35131 Padua, Italy

[22] INAF Osservatorio Astron, I-34014 Trieste, Italy

[23] CSIC, Inst Astrofis Andalucia, E-18008 Granada, Spain

[24] Natl Cent Univ, Grad Inst Astron, Chungli 32054, Taiwan

[25] European Space Astron Ctr ESA, Operat Dept, Madrid 28691, Spain

[26] Tech Univ Carolo Wilhelmina Braunschweig, Inst Datentech & Kommunikat Netze, D-38106 Braunschweig, Germany

来源：

ASTRONOMY & ASTROPHYSICS | 2015年 / 583卷

关键词：

comets: general; techniques: image processing; methods: laboratory: solid state; WATER ICE; COMET; 67P/CHURYUMOV-GERASIMENKO; SUBLIMATION; NUCLEUS; GEOMORPHOLOGY; EVOLUTION; BODIES; SYSTEM;

D O I：

10.1051/0004-6361/201525977

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

Since OSIRIS started acquiring high-resolution observations of the surface of the nucleus of comet 67P/Churyumov-Gerasimenko, over one hundred meter-sized bright spots have been identified in numerous types of geomorphologic regions, but mostly located in areas receiving low insolation. The bright spots are either clustered, in debris fields close to decameter-high cliffs, or isolated without structural relation to the surrounding terrain. They can be up to ten times brighter than the average surface of the comet at visible wavelengths and display a significantly bluer spectrum. They do not exhibit significant changes over a period of a few weeks. All these observations are consistent with exposure of water ice at the surface of boulders produced by dislocation of the weakly consolidated layers that cover large areas of the nucleus. Laboratory experiments show that under simulated comet surface conditions, analog samples acquire a vertical stratification with an uppermost porous mantle of refractory dust overlaying a layer of hard ice formed by recondensation or sintering under the insulating dust mantle. The evolution of the visible spectrophotometric properties of samples during sublimation is consistent with the contrasts of brightness and color seen at the surface of the nucleus. Clustered bright spots are formed by the collapse of overhangs that is triggered by mass wasting of deeper layers. Isolated spots might be the result of the emission of boulders at low velocity that are redepositioned in other regions.

引用

页数：16

共 38 条

[1] Geomorphology of the Imhotep region on comet 67P/Churyumov-Gerasimenko from OSIRIS observations [J].

Auger, A. -T. ;

Groussin, O. ;

Jorda, L. ;

Bouley, S. ;

Gaskell, R. ;

Lamy, P. L. ;

Capanna, C. ;

Thomas, N. ;

Pommerol, A. ;

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. ;

Davidsson, B. ;

Debei, S. ;

De Cecco, M. ;

El-Maarry, M. R. ;

Fornasier, S. ;

Fulle, M. ;

Gutierrez, P. J. ;

Guettler, C. ;

Hviid, S. ;

Ip, W. -H. ;

Knollenberg, J. ;

Kramm, J. -R. ;

Kuehrt, E. ;

Kueppers, M. ;

La Forgia, F. ;

Lara, L. M. ;

Lazzarin, M. ;

Lopez Moreno, J. J. ;

Marchi, S. ;

Marzari, F. ;

Massironi, M. ;

Michalik, H. ;

Naletto, G. ;

Oklay, N. ;

Pajola, M. ;

Sabau, L. ;

Tubiana, C. ;

Vincent, J. -B. .

ASTRONOMY & ASTROPHYSICS, 2015, 583

[2] Space missions to small bodies: asteroids and cometary nuclei [J].

Barucci, M. A. ;

Dotto, E. ;

Levasseur-Regourd, A. C. .

ASTRONOMY AND ASTROPHYSICS REVIEW, 2011, 19 :1-29

[3] INTERFACE KINETICS OF THE GROWTH AND EVAPORATION OF ICE SINGLE-CRYSTALS FROM THE VAPOR-PHASE .2. MEASUREMENTS IN A PURE WATER-VAPOR ENVIRONMENT [J].

BECKMANN, W ;

LACMANN, R .

JOURNAL OF CRYSTAL GROWTH, 1982, 58 (02) :433-442

[4] Experimental and theoretical simulations of ice sublimation with implications for the chemical, isotopic, and physical evolution of icy objects [J].

Brown, Robert H. ;

Lauretta, Dante S. ;

Schmidt, Britney ;

Moores, John .

PLANETARY AND SPACE SCIENCE, 2012, 60 (01) :166-180

[5] The organic-rich surface of comet 67P/Churyumov-Gerasimenko as seen by VIRTIS/Rosetta [J].

Capaccioni, F. ;

Coradini, A. ;

Filacchione, G. ;

Erard, S. ;

Arnold, G. ;

Drossart, P. ;

De Sanctis, M. C. ;

Bockelee-Morvan, D. ;

Capria, M. T. ;

Tosi, F. ;

Leyrat, C. ;

Schmitt, B. ;

Quirico, E. ;

Cerroni, P. ;

Mennella, V. ;

Raponi, A. ;

Ciarniello, M. ;

McCord, T. ;

Moroz, L. ;

Palomba, E. ;

Ammannito, E. ;

Barucci, M. A. ;

Bellucci, G. ;

Benkhoff, J. ;

Bibring, J. P. ;

Blanco, A. ;

Blecka, M. ;

Carlson, R. ;

Carsenty, U. ;

Colangeli, L. ;

Combes, M. ;

Combi, M. ;

Crovisier, J. ;

Encrenaz, T. ;

Federico, C. ;

Fink, U. ;

Fonti, S. ;

Ip, W. H. ;

Irwin, P. ;

Jaumann, R. ;

Kuehrt, E. ;

Langevin, Y. ;

Magni, G. ;

Mottola, S. ;

Orofino, V. ;

Palumbo, P. ;

Piccioni, G. ;

Schade, U. ;

Taylor, F. ;

Tiphene, D. .

SCIENCE, 2015, 347 (6220)

[6] Chemical Characterization of Titan's Tholins: Solubility, Morphology and Molecular Structure Revisited [J].

Carrasco, N. ;

Schmitz-Afonso, I. ;

Bonnet, J-Y. ;

Quirico, E. ;

Thissen, R. ;

Dutuit, Odile ;

Bagag, A. ;

Laprevote, O. ;

Buch, A. ;

Giulani, A. ;

Adande, Gilles ;

Ouni, F. ;

Hadamcik, E. ;

Szopa, C. ;

Cernogora, G. .

JOURNAL OF PHYSICAL CHEMISTRY A, 2009, 113 (42) :11195-11203

[7] VIRTIS: The imaging spectrometer of the ROSETTA mission [J].

Coradini, A ;

Capaccioni, F ;

Drossart, P ;

Semery, A ;

Arnold, G ;

Schade, U .

EXPLORATION OF SMALL BODIES IN THE SOLAR SYSTEM: I. INITIAL RESULTS AND FUTURE PROSPECTS, 1999, 24 (09) :1095-1104

[8] DYNAMIC FAILURE IN SOLIDS [J].

CURRAN, DR ;

SEAMAN, L ;

SHOCKEY, DA .

PHYSICS TODAY, 1977, 30 (01) :46-&

[9] Orbital elements of the material surrounding comet 67P/Churyumov-Gerasimenko [J].

Davidsson, B. J. R. ;

Gutierrez, P. J. ;

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. ;

Debei, S. ;

De Cecco, M. ;

Fornasier, S. ;

Fulle, M. ;

Groussin, O. ;

Guettler, C. ;

Hviid, S. F. ;

Ip, W. -H. ;

Jorda, L. ;

Knollenberg, J. ;

Kovacs, G. ;

Kramm, J. -R. ;

Kuehrt, E. ;

Kueppers, M. ;

La Forgia, F. ;

Lara, L. M. ;

Lazzarin, M. ;

Lopez Moreno, J. J. ;

Lowry, S. ;

Magrin, S. ;

Marzari, E. ;

Michalik, H. ;

Moissl-Fraund, R. ;

Naletto, G. ;

Oklay, N. ;

Pajola, M. ;

Snodgrass, C. ;

Thomas, N. ;

Tubiana, C. ;

Vincent, J. -B. .

ASTRONOMY & ASTROPHYSICS, 2015, 583

[10] Regional surface morphology of comet 67P/Churyumov-Gerasimenko from Rosetta/OSIRIS images [J].

El-Maarry, M. R. ;

Thomas, N. ;

Giacomini, L. ;

Massironi, M. ;

Pajola, M. ;

Marschall, R. ;

Gracia-Berna, A. ;

Sierks, H. ;

Barbieri, C. ;

Lamy, P. L. ;

Rodrigo, R. ;

Rickman, H. ;

Koschny, D. ;

Keller, H. U. ;

Agarwal, J. ;

A'Hearn, M. 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. ;

Guettler, C. ;

Fornasier, S. ;

Fulle, M. ;

Groussin, O. ;

Gutierrez, P. J. ;

Hviid, S. F. ;

Ip, W. -H. ;

Jorda, L. ;

Knollenberg, J. ;

Kovacs, G. ;

Kramm, J. -R. ;

Kuehrt, E. ;

Kueppers, M. ;

La Forgia, F. ;

Lara, L. M. ;

Lazzarin, M. ;

Lopez Moreno, J. J. ;

Marchi, S. ;

Marzari, F. ;

Michalik, H. ;

Naletto, G. ;

Oklay, N. ;

Pommerol, A. .

ASTRONOMY & ASTROPHYSICS, 2015, 583

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