TY - JOUR
A1 - Markus, Kathrin
A1 - Moroz, Lyuba
A1 - Arnold, Gabriele
A1 - Henckel, Daniela
A1 - Hiesinger, Harald
A1 - Rohrbach, Arno
A1 - Klemme, Stephan
T1 - Reflectance spectra of synthetic Fe-free ortho- and clinoenstatites in the UV/VIS/IR and implications for remote sensing detection of Fe-free pyroxenes on planetary surfaces
JF - Planetary and space science
N2 - Both enstatite spectra are very bright in the VIS and NIR and show almost neutral to slightly bluish spectral slopes with a steep absorption in the UV. Very low iron in the enstatites (below similar to 0.04 wt% FeO) already results in weak albeit noticeable absorptions in the VNIR between 0.4 and 0.9 mu m. Orthoenstatite and clinoenstatite are not distinguishable based only on their spectra in the VIS and NIR. At the Reststrahlen bands in the MIR a systematic difference in the number and exact position of local minima at similar to 10 mu m between clinoenstatite and orthoenstatite is evident. This can be used to discern between the polymorphs in this wavelength range. Additionally, we can distinguish between Fe-free low- and high-Ca pyroxenes in the MIR.
KW - Reflectance spectroscopy
KW - Remote sensing
KW - Enstatite
KW - Synthetic pyroxene
KW - Analog material
Y1 - 2018
U6 - https://doi.org/10.1016/j.pss.2018.04.006
SN - 0032-0633
VL - 159
SP - 43
EP - 55
PB - Elsevier
CY - Oxford
ER -
TY - CHAP
A1 - Arnold, Gabriele
T1 - Beiträge zur spektralen Fernerkundung fester planetarer Oberflächen
N2 - Dr. Gabriele Arnold ist Leiterin des Bereichs Optische Informationssyteme am Institut für Planetenforschung des Deutschen Zentrums für Luft- und Raumfahrt (DLR) in Berlin-Adlershof
Interdisziplinäres Zentrum für Musterdynamik und Angewandte Fernerkundung Workshop vom 9. - 10. Februar 2006
Y1 - 2006
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-7235
N1 - [Poster]
ER -
TY - THES
A1 - Arnold, Gabriele
T1 - Spektrale Fernerkundung der terristrischen Planetoberflächen von Merkur, Venus und Mars vom visuellen bis in den infraroten Wellenlängenbereich
Y1 - 2013
CY - Potsdam
ER -
TY - JOUR
A1 - Quirico, E.
A1 - Moroz, Liubov V.
A1 - Schmitt, B.
A1 - Arnold, Gabriele
A1 - Faure, M.
A1 - Beck, P.
A1 - Bonal, L.
A1 - Ciarniello, M.
A1 - Capaccioni, F.
A1 - Filacchione, G.
A1 - Erard, S.
A1 - Leyrat, C.
A1 - Bockelee-Morvan, D.
A1 - Zinzi, A.
A1 - Palomba, E.
A1 - Drossart, P.
A1 - Tosi, F.
A1 - Capria, M. T.
A1 - De Sanctis, M. C.
A1 - Raponi, A.
A1 - Fonti, S.
A1 - Mancarella, F.
A1 - Orofino, V.
A1 - Barucci, A.
A1 - Blecka, M. I.
A1 - Carlson, R.
A1 - Despan, D.
A1 - Faure, A.
A1 - Fornasier, S.
A1 - Gudipati, M. S.
A1 - Longobardo, A.
A1 - Markus, K.
A1 - Mennella, V.
A1 - Merlin, F.
A1 - Piccioni, G.
A1 - Rousseau, B.
A1 - Taylor, F.
T1 - Refractory and semi-volatile organics at the surface of comet 67P/Churyumov-Gerasimenko: Insights from the VIRTIS/Rosetta imaging spectrometer
JF - Icarus : international journal of solar system studies
N2 - The VIRTIS (Visible, Infrared and Thermal Imaging Spectrometer) instrument aboard the Rosetta spacecraft has performed extensive spectral mapping of the surface of comet 67P/Churyumov-Gerasimenko in the range 0.3-5 mu m. The reflectance spectra collected across the surface display a low reflectance factor over the whole spectral range, two spectral slopes in the visible and near-infrared ranges and a broad absorption band centered at 3.2 mu m. The first two of these characteristics are typical of dark small bodies of the Solar System and are difficult to interpret in terms of composition. Moreover, solar wind irradiation may modify the structure and composition of surface materials and there is no unequivocal interpretation of these spectra devoid of vibrational bands. To circumvent these problems, we consider the composition of cometary grains analyzed in the laboratory to constrain the nature of the cometary materials and consider results on surface rejuvenation and solar wind processing provided by the OSIRIS and ROSINA instruments, respectively. Our results lead to five main conclusions: (i) The low albedo of comet 67P/CG is accounted for by a dark refractory polyaromatic carbonaceous component mixed with opaque minerals. VIRTIS data do not provide direct insights into the nature of these opaque minerals. However, according to the composition of cometary grains analyzed in the laboratory, we infer that they consist of Fe-Ni alloys and FeS sulfides. (ii) A semi-volatile component, consisting of a complex mix of low weight molecular species not volatilized at T similar to 220 K, is likely a major carrier of the 3.2 p.m band. Water ice contributes significantly to this feature in the neck region but not in other regions of the comet. COOH in carboxylic acids is the only chemical group that encompasses the broad width of this feature. It appears as a highly plausible candidate along with the NH4+ ion. (iii) Photolytic/thermal residues, produced in the laboratory from interstellar ice analogs, are potentially good spectral analogs. (iv) No hydrated minerals were identified and our data support the lack of genetic links with the CI, CR and CM primitive chondrites. This concerns in particular the Orgueil chondrite, previously suspected to have been of cometary origin. (v) The comparison between fresh and aged terrains revealed no effect of solar wind irradiation on the 3.2 mu m band. This is consistent with the presence of efficient resurfacing processes such as dust transport from the interior to the surface, as revealed by the OSIRIS camera. (C) 2016 Elsevier Inc. All rights reserved.
KW - Comets
KW - Organic chemistry
KW - Infrared observations
KW - Meteorites
KW - Spectrophotometry
Y1 - 2016
U6 - https://doi.org/10.1016/j.icarus.2016.02.028
SN - 0019-1035
SN - 1090-2643
VL - 272
SP - 32
EP - 47
PB - Elsevier
CY - San Diego
ER -
TY - JOUR
A1 - Kappel, David
A1 - Arnold, Gabriele
A1 - Haus, Rainer
T1 - Multi-spectrum retrieval of Venus IR surface emissivity maps from VIRTIS/VEX nightside measurements at Themis Regio
JF - Icarus : international journal of solar system studies
N2 - Renormalized emissivity maps of Themis Regio at the three surface windows are determined from 64 measurement repetitions. Retrieval errors are estimated by a statistical evaluation of maps derived from various disjoint selections of spectra and using different assumptions on the interfering parameters. Double standard deviation errors for the three surface windows amount to 3%, 8%, and 4%, respectively, allowing geologic interpretation. A comparison to results from an earlier error analysis based on synthetic spectra shows that unconsidered time variations of interfering atmospheric parameters are a major error source. Spatial variations of the 1.02 mu m surface emissivity of 20% that correspond to the difference between unweathered granitic and basaltic rocks would be easily detectable, but such variations are ruled out for the studied target area. Emissivity anomalies of up to 8% are detected at both 1.02 and 1.18 mu m. At present sensitivity, no anomalies are identified at 1.10 mu m, but anomalies exceeding the determined error level can be excluded. With single standard deviation significance, all three maps show interesting spatial emissivity variations. (C) 2015 Elsevier Inc. All rights reserved.
KW - Venus, surface
KW - Infrared observations
KW - Radiative transfer
Y1 - 2016
U6 - https://doi.org/10.1016/j.icarus.2015.10.014
SN - 0019-1035
SN - 1090-2643
VL - 265
SP - 42
EP - 62
PB - Elsevier
CY - San Diego
ER -