TY - JOUR
T1 - Detection of serpentine in exogenic carbonaceous chondrite material on Vesta from Dawn FC data
AU - Nathues, Andreas
AU - Hoffmann, Martin
AU - Cloutis, Edward A.
AU - Schäfer, Michael
AU - Reddy, Vishnu
AU - Christensen, Ulrich
AU - Sierks, Holger
AU - Thangjam, Guneshwar Singh
AU - Le Corre, Lucille
AU - Mengel, Kurt
AU - Vincent, Jean Baptist
AU - Russell, Christopher T.
AU - Prettyman, Tom
AU - Schmedemann, Nico
AU - Kneissl, Thomas
AU - Raymond, Carol
AU - Gutierrez-Marques, Pablo
AU - Hall, Ian
AU - Büttner, Irene
N1 - Funding Information:
The authors would like to thank the Dawn Flight Operations team for a successful Vesta phase. AN would like to thank MPS, DLR and IDA colleagues which worked hard to design, built and test the Framing Cameras. The camera system was developed and built under the leadership of the Max-Planck-Institute for Solar System Research. The Institute for Planetary Research of the German Space Agency DLR provided the Front End Electronics as well as the CCD. The Institute of Computer and Communication Network Engineering provided the main electronics of the cameras. The project is financially supported by the Max Planck Society , DLR , and NASA/JPL .
PY - 2014/9/1
Y1 - 2014/9/1
N2 - The Dawn mission's Framing Camera (FC) observed Asteroid (4) Vesta in 2011 and 2012 using seven color filters and one clear filter from different orbits. In the present paper we analyze recalibrated HAMO color cubes (spatial resolution ~60. m/pixel) with a focus on dark material (DM). We present a definition of highly concentrated DM based on spectral parameters, subsequently map the DM across the Vestan surface, geologically classify DM, study its spectral properties on global and local scales, and finally, compare the FC in-flight color data with laboratory spectra.We have discovered an absorption band centered at 0.72. μm in localities of DM that show the lowest albedo values by using FC data as well as spectral information from Dawn's imaging spectrometer VIR. Such localities are contained within impact-exposed outcrops on inner crater walls and ejecta material. Comparisons between spectral FC in-flight data, and laboratory spectra of meteorites and mineral mixtures in the wavelength range 0.4-1.0. μm, revealed that the absorption band can be attributed to the mineral serpentine, which is typically present in CM chondrites. Dark material in its purest form is rare on Vesta's surface and is distributed globally in a non-uniform manner. Our findings confirm the hypothesis of an exogenic origin of the DM by the infall of carbonaceous chondritic material, likely of CM type. It further confirms the hypothesis that most of the DM was deposited by the Veneneia impact.
AB - The Dawn mission's Framing Camera (FC) observed Asteroid (4) Vesta in 2011 and 2012 using seven color filters and one clear filter from different orbits. In the present paper we analyze recalibrated HAMO color cubes (spatial resolution ~60. m/pixel) with a focus on dark material (DM). We present a definition of highly concentrated DM based on spectral parameters, subsequently map the DM across the Vestan surface, geologically classify DM, study its spectral properties on global and local scales, and finally, compare the FC in-flight color data with laboratory spectra.We have discovered an absorption band centered at 0.72. μm in localities of DM that show the lowest albedo values by using FC data as well as spectral information from Dawn's imaging spectrometer VIR. Such localities are contained within impact-exposed outcrops on inner crater walls and ejecta material. Comparisons between spectral FC in-flight data, and laboratory spectra of meteorites and mineral mixtures in the wavelength range 0.4-1.0. μm, revealed that the absorption band can be attributed to the mineral serpentine, which is typically present in CM chondrites. Dark material in its purest form is rare on Vesta's surface and is distributed globally in a non-uniform manner. Our findings confirm the hypothesis of an exogenic origin of the DM by the infall of carbonaceous chondritic material, likely of CM type. It further confirms the hypothesis that most of the DM was deposited by the Veneneia impact.
KW - Asteroid vesta
KW - Asteroids, composition
KW - Mineralogy
KW - Spectroscopy
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U2 - 10.1016/j.icarus.2014.06.003
DO - 10.1016/j.icarus.2014.06.003
M3 - Article
AN - SCOPUS:84903840421
SN - 0019-1035
VL - 239
SP - 222
EP - 237
JO - Icarus
JF - Icarus
ER -