TY  - JOUR
A1  - Tosi, Federico
A1  - Capaccioni, F.
A1  - Capria, M. T.
A1  - Mottola, Stefano
A1  - Zinzi, A.
A1  - Ciarniello, M.
A1  - Filacchione, G.
A1  - Hofstadter, M.
A1  - Fonti, S.
A1  - Formisano, M.
A1  - Kappel, David
A1  - Kührt, E.
A1  - Leyrat, C.
A1  - Vincent, J-B
A1  - Arnold, G.
A1  - De Sanctis, M. C.
A1  - Longobardo, Andrea
A1  - Palomba, E.
A1  - Raponi, A.
A1  - Rousseau, Batiste
A1  - Schmitt, Bernard
A1  - Barucci, Maria Antonietta
A1  - Bellucci, Giancarlo
A1  - Benkhoff, Johannes
A1  - Bockelee-Morvan, D.
A1  - Cerroni, P.
A1  - Combe, J-Ph
A1  - Despan, D.
A1  - Erard, Stéphane
A1  - Mancarella, F.
A1  - McCord, T. B.
A1  - Migliorini, Alessandra
A1  - Orofino, V
A1  - Piccioni, G.
T1  - The changing temperature of the nucleus of comet 67P induced by morphological and seasonal effects
JF  - Nature astronomy
N2  - Knowledge of the surface temperature distribution on a comet’s nucleus and its temporal evolution at different timescales is key to constraining its thermophysical properties and understanding the physical processes that take place at and below the surface. Here we report on time-resolved maps of comet 67P/Churyumov–Gerasimenko retrieved on the basis of infrared data acquired by the Visible InfraRed and Thermal Imaging Spectrometer (VIRTIS) onboard the Rosetta orbiter in 2014, over a roughly two-month period in the pre-perihelion phase at heliocentric distances between 3.62 and 3.31 au from the Sun. We find that at a spatial resolution ≤15 m per pixel, the measured temperatures point out the major effect that self-heating, due to the complex shape of the nucleus, has on the diurnal temperature variation. The bilobate nucleus of comet 67P also induces daytime shadowing effects, which result in large thermal gradients. Over longer periods, VIRTIS-derived temperature values reveal seasonal changes driven by decreasing heliocentric distance combined with an increasing abundance of ice within the uppermost centimetre-thick layer, which implies the possibility of having a largely pristine nucleus interior already in the shallow subsurface
Y1  - 2019
U6  - https://doi.org/10.1038/s41550-019-0740-0
SN  - 2397-3366
VL  - 3
IS  - 7
SP  - 649
EP  - 658
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - JOUR
A1  - Toy, Virginia Gail
A1  - Sutherland, Rupert
A1  - Townend, John
A1  - Allen, Michael J.
A1  - Becroft, Leeza
A1  - Boles, Austin
A1  - Boulton, Carolyn
A1  - Carpenter, Brett
A1  - Cooper, Alan
A1  - Cox, Simon C.
A1  - Daube, Christopher
A1  - Faulkner, D. R.
A1  - Halfpenny, Angela
A1  - Kato, Naoki
A1  - Keys, Stephen
A1  - Kirilova, Martina
A1  - Kometani, Yusuke
A1  - Little, Timothy
A1  - Mariani, Elisabetta
A1  - Melosh, Benjamin
A1  - Menzies, Catriona D.
A1  - Morales, Luiz
A1  - Morgan, Chance
A1  - Mori, Hiroshi
A1  - Niemeijer, Andre
A1  - Norris, Richard
A1  - Prior, David
A1  - Sauer, Katrina
A1  - Schleicher, Anja Maria
A1  - Shigematsu, Norio
A1  - Teagle, Damon A. H.
A1  - Tobin, Harold
A1  - Valdez, Robert
A1  - Williams, Jack
A1  - Yeo, Samantha
A1  - Baratin, Laura-May
A1  - Barth, Nicolas
A1  - Benson, Adrian
A1  - Boese, Carolin
A1  - Célérier, Bernard
A1  - Chamberlain, Calum J.
A1  - Conze, Ronald
A1  - Coussens, Jamie
A1  - Craw, Lisa
A1  - Doan, Mai-Linh
A1  - Eccles, Jennifer
A1  - Grieve, Jason
A1  - Grochowski, Julia
A1  - Gulley, Anton
A1  - Howarth, Jamie
A1  - Jacobs, Katrina
A1  - Janku-Capova, Lucie
A1  - Jeppson, Tamara
A1  - Langridge, Robert
A1  - Mallyon, Deirdre
A1  - Marx, Ray
A1  - Massiot, Cécile
A1  - Mathewson, Loren
A1  - Moore, Josephine
A1  - Nishikawa, Osamu
A1  - Pooley, Brent
A1  - Pyne, Alex
A1  - Savage, Martha K.
A1  - Schmitt, Doug
A1  - Taylor-Offord, Sam
A1  - Upton, Phaedra
A1  - Weaver, Konrad C.
A1  - Wiersberg, Thomas
A1  - Zimmer, Martin
T1  - Bedrock geology of DFDP-2B, central Alpine Fault, New Zealand
JF  - New Zealand journal of geology and geophysics : an international journal of the geoscience of New Zealand, the Pacific Rim, and Antarctica ; NZJG
N2  - During the second phase of the Alpine Fault, Deep Fault Drilling Project (DFDP) in the Whataroa River, South Westland, New Zealand, bedrock was encountered in the DFDP-2B borehole from 238.5–893.2 m Measured Depth (MD). Continuous sampling and meso- to microscale characterisation of whole rock cuttings established that, in sequence, the borehole sampled amphibolite facies, Torlesse Composite Terrane-derived schists, protomylonites and mylonites, terminating 200–400 m above an Alpine Fault Principal Slip Zone (PSZ) with a maximum dip of 62°. The most diagnostic structural features of increasing PSZ proximity were the occurrence of shear bands and reduction in mean quartz grain sizes. A change in composition to greater mica:quartz + feldspar, most markedly below c. 700 m MD, is inferred to result from either heterogeneous sampling or a change in lithology related to alteration. Major oxide variations suggest the fault-proximal Alpine Fault alteration zone, as previously defined in DFDP-1 core, was not sampled.
KW  - Alpine Fault
KW  - New Zealand
KW  - scientific drilling
KW  - mylonite
KW  - cataclasite
Y1  - 2017
U6  - https://doi.org/10.1080/00288306.2017.1375533
SN  - 0028-8306
SN  - 1175-8791
VL  - 60
IS  - 4
SP  - 497
EP  - 518
PB  - Taylor & Francis
CY  - Abingdon
ER  - 
TY  - JOUR
A1  - Poch, Olivier
A1  - Istiqomah, Istiqomah
A1  - Quirico, Eric
A1  - Beck, Pierre
A1  - Schmitt, Bernard
A1  - Theulé, Patrice
A1  - Faure, Alexandre
A1  - Hily-Blant, Pierre
A1  - Bonal, Lydie
A1  - Kappel, David
T1  - Ammonium salts are a reservoir of nitrogen on a cometary nucleus and possibly on some asteroids
JF  - Science
N2  - The measured nitrogen-to-carbon ratio in comets is lower than for the Sun, a discrepancy which could be alleviated if there is an unknown reservoir of nitrogen in comets. The nucleus of comet 67P/Churyumov-Gerasimenko exhibits an unidentified broad spectral reflectance feature around 3.2 micrometers, which is ubiquitous across its surface. On the basis of laboratory experiments, we attribute this absorption band to ammonium salts mixed with dust on the surface. The depth of the band indicates that semivolatile ammonium salts are a substantial reservoir of nitrogen in the comet, potentially dominating over refractory organic matter and more volatile species. Similar absorption features appear in the spectra of some asteroids, implying a compositional link between asteroids, comets, and the parent interstellar cloud.
KW  - resolution infrared-spectroscopy
KW  - ice absorption features
KW  - young stellar objects
KW  - exposed water ice
KW  - MU-M
KW  - bidirectional reflectance
KW  - murchison meteorite
KW  - interstellar ice
KW  - spectra
KW  - surface
Y1  - 2020
U6  - https://doi.org/10.1126/science.aaw7462
SN  - 1095-9203
SN  - 0036-8075
VL  - 367
IS  - 6483
SP  - 1
EP  - 8
PB  - AAAS, American Association for the Advancement of Science
CY  - Washington, DC
ER  - 
TY  - GEN
A1  - Poch, Olivier
A1  - Istiqomah, Istiqomah
A1  - Quirico, Eric
A1  - Beck, Pierre
A1  - Schmitt, Bernard
A1  - Theulé, Patrice
A1  - Faure, Alexandre
A1  - Hily-Blant, Pierre
A1  - Bonal, Lydie
A1  - Kappel, David
T1  - Ammonium salts are a reservoir of nitrogen on a cometary nucleus and possibly on some asteroids
T2  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - The measured nitrogen-to-carbon ratio in comets is lower than for the Sun, a discrepancy which could be alleviated if there is an unknown reservoir of nitrogen in comets. The nucleus of comet 67P/Churyumov-Gerasimenko exhibits an unidentified broad spectral reflectance feature around 3.2 micrometers, which is ubiquitous across its surface. On the basis of laboratory experiments, we attribute this absorption band to ammonium salts mixed with dust on the surface. The depth of the band indicates that semivolatile ammonium salts are a substantial reservoir of nitrogen in the comet, potentially dominating over refractory organic matter and more volatile species. Similar absorption features appear in the spectra of some asteroids, implying a compositional link between asteroids, comets, and the parent interstellar cloud.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1389 
KW  - resolution infrared-spectroscopy
KW  - ice absorption features
KW  - young stellar objects
KW  - exposed water ice
KW  - MU-M
KW  - bidirectional reflectance
KW  - murchison meteorite
KW  - interstellar ice
KW  - spectra
KW  - surface
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-513751
SN  - 1866-8372
N1  - This secondary publication was withdrawn for copyright reasons.
IS  - 6483
ER  -