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4. Consus Crater on Ceres: Ammonium‐Enriched Brines in Exchange With Phyllosilicates?

Author

Nathues, A., Hoffmann, M., Sarkar, R., Singh, P., Hernandez, J., Pasckert, J. H., Schmedemann, N., Thangjam, G., Cloutis, E., Mengel, K., and Coutelier, M.

Subjects
IR spectrometers, DWARF planets, REMOTE sensing, SOLAR system, SMECTITE, IMPACT craters
Abstract

Ceres is a partially differentiated dwarf planet located in the main asteroid belt. Consus crater (diameter ∼64 km) is one of the oldest impact features (∼450 Ma) on the Cerean surface that surprisingly still shows a large variety of color lithologies, including exposures of bright material, which are thought to be brine residues. Here, we present new results that help in understanding the structure and composition of the Cerean crust. These results were deduced by using newly processed Dawn Framing Camera (FC) color imagery and FC clear filter images combined with infrared spectral data of Dawn's Visible and Infrared Spectrometer (VIR). Consus exhibits a variety of color lithologies, which we describe in detail. Interestingly, we found three spectrally different types of bright material exposed by a large old crater on Consus' floor. One of these, the yellowish bright material (Nathues et al., 2023, https://www.hou.usra.edu/meetings/lpsc2023/pdf/1073.pdf) and its modification, shows spectral signatures consistent with ammonium‐enriched smectites. We hypothesize that the ammonium in these smectites stems from contact with ascending brines, originating from a low‐lying former brine ocean that has been enriched in ammonium during the differentiation and freezing process of the Cerean crust. This enrichment is mainly due to ammonium uptake by sheet silicates. If such an ammonium enrichment occurred over long‐time scales on a global scale, this process may explain the vast presence of ammonium on the Cerean surface. Therefore, an outer solar system origin of Ceres is possibly not needed to explain the global presence of ammonium. Plain Language Summary: Ceres is the largest object in the asteroid belt and surprisingly exhibits surface features formed by recent cryo‐volcanism, although evolution models predicted an inactive, completely frozen body. Cryo‐volcanism possibly stems from a brine layer at the crust‐mantle transition. The global presence of ammonium on the Cerean surface led to the conclusion of a potential outer solar system origin of Ceres. Here, we investigate the structure of its crust, by studying one of the older, but still mineralogical diverse, impact craters that excavated originally low‐lying materials. For our study, we are using data of the Dawn Framing Camera, spectral data of the Visible and Infrared Spectrometer as well as several geoscientific remote sensing methods. We describe "yellowish bright material" for the first time (Nathues et al., 2023, https://www.hou.usra.edu/meetings/lpsc2023/pdf/1073.pdf), that is spectrally unique in our color data and exhibits a strong absorption feature in the near‐infrared caused by ammonium. We hypothesize that the ammonium enrichment of this surface material is mainly a consequence of an ammonium exchange between rising brines and near‐surface phyllosilicates. If true, this would strengthen the case for the existence of a low‐lying ammonium‐rich brine layer, which in turn could weaken the hypothesis of an outer solar system origin for Ceres. Key Points: The old impact crater Consus still shows a large variety of color lithologiesThe yellow bright material lithology is ammonium‐enrichedWe hypothesize that this ammonium stems from ascending originally low‐lying brines [ABSTRACT FROM AUTHOR]

Published
2024
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5. Pitted terrains on (1) Ceres and implications for shallow subsurface volatile distribution

Author

Sizemore, HG, Platz, T, Schorghofer, N, Prettyman, TH, De Sanctis, MC, Crown, DA, Schmedemann, N, Neesemann, A, Kneissl, T, Marchi, S, Schenk, PM, Bland, MT, Schmidt, BE, Hughson, KHG, Tosi, F, Zambon, F, Mest, SC, Yingst, RA, Williams, DA, Russell, CT, and Raymond, CA

Subjects
Ceres, craters, geomorphology, ground ice, pitted terrain, volatiles, Meteorology & Atmospheric Sciences
Abstract

Prior to the arrival of the Dawn spacecraft at Ceres, the dwarf planet was anticipated to be ice-rich. Searches for morphological features related to ice have been ongoing during Dawn's mission at Ceres. Here we report the identification of pitted terrains associated with fresh Cerean impact craters. The Cerean pitted terrains exhibit strong morphological similarities to pitted materials previously identified on Mars (where ice is implicated in pit development) and Vesta (where the presence of ice is debated). We employ numerical models to investigate the formation of pitted materials on Ceres and discuss the relative importance of water ice and other volatiles in pit development there. We conclude that water ice likely plays an important role in pit development on Ceres. Similar pitted terrains may be common in the asteroid belt and may be of interest to future missions motivated by both astrobiology and in situ resource utilization.

Published
2017

10. Cratering on Ceres: Implications for its crust and evolution

Author

Hiesinger, H., Marchi, S., Schmedemann, N., Schenk, P., Pasckert, J. H., Neesemann, A., O'Brien, D. P., Kneissl, T., Ermakov, A. I., Fu, R. R., Bland, M. T., Nathues, A., Platz, T., Williams, D. A., Jaumann, R., Castillo-Rogez, J. C., Ruesch, O., Schmidt, B., Park, R. S., Preusker, F., Buczkowski, D. L., Russell, C. T., and Raymond, C. A.

Published
2016

11. Cryovolcanism on Ceres

Author

Ruesch, O., Platz, T., Schenk, P., McFadden, L. A., Castillo-Rogez, J. C., Quick, L. C., Byrne, S., Preusker, F., O'Brien, D. P., Schmedemann, N., Williams, D. A., Li, J.-Y., Bland, M. T., Hiesinger, H., Kneissl, T., Neesemann, A., Schaefer, M., Pasckert, J. H., Schmidt, B. E., Buczkowski, D. L., Sykes, M. V., Nathues, A., Roatsch, T., Hoffmann, M., Raymond, C. A., and Russell, C. T.

Published
2016

14. Mass movement on Vesta at steep scarps and crater rims

Author

Krohn, K., Jaumann, R., Otto, K., Hoogenboom, T., Wagner, R., Buczkowski, D.L., Garry, B., Williams, D.A., Yingst, R.A., Scully, J., De Sanctis, M.C., Kneissl, T., Schmedemann, N., Kersten, E., Stephan, K., Matz, K.-D., Pieters, C.M., Preusker, F., Roatsch, T., Schenk, P., Russell, C.T., and Raymond, C.A.

Published
2014
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19. Mars Express investigations of Phobos and Deimos

Author

Witasse, O., Duxbury, T., Chicarro, A., Altobelli, N., Andert, T., Aronica, A., Barabash, S., Bertaux, J.-L., Bibring, J.-P., Cardesin-Moinelo, A., Cichetti, A., Companys, V., Dehant, V., Denis, M., Formisano, V., Futaana, Y., Giuranna, M., Gondet, B., Heather, D., Hoffmann, H., Holmström, M., Manaud, N., Martin, P., Matz, K.-D., Montmessin, F., Morley, T., Mueller, M., Neukum, G., Oberst, J., Orosei, R., Pätzold, M., Picardi, G., Pischel, R., Plaut, J.J., Reberac, A., Pardo Voss, P., Roatsch, T., Rosenblatt, P., Remus, S., Schmedemann, N., Willner, K., and Zegers, T.

Published
2014
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21. Sublimation in bright spots on (1) Ceres

Author

Nathues, A., Hoffmann, M., Schaefer, M., Le Corre, L., Reddy, V., Platz, T., Cloutis, E.A., Christensen, U., Kneissl, T., Li, J.-Y., Mengel, K., Schmedemann, N., Schaefer, T., Russell, C.T., Applin, D.M., Buczkowski, D.L., Izawa, M.R.M., Keller, H.U., O'Brien, D.P., Pieters, C.M., Raymond, C.A., Ripken, J., Schenk, P.M., Schmidt, B.E., Sierks, H., Sykes, M.V., Thangjam, G.S., and Vincent, J.-B.

Subjects
Ceres (Asteroid) -- Observations, Environmental issues, Science and technology, Zoology and wildlife conservation, Observations
Abstract

The dwarf planet (1) Ceres, the largest object in the main asteroid belt (1) with a mean diameter of about 950 kilometres, is located at a mean distance from the Sun of about 2.8 astronomical units (one astronomical unit is the Earth-Sun distance). Thermal evolution models suggest that it is a differentiated body with potential geological activity (2,3). Unlike on the icy satellites of Jupiter and Saturn, where tidal forces are responsible for spewing briny water into space, no tidal forces are acting on Ceres. In the absence of such forces, most objects in the main asteroid belt are expected to be geologically inert. The recent discovery (4) of water vapour absorption near Ceres and previous detection of bound water and OH near and on Ceres (refs 5-7) have raised interest in the possible presence of surface ice. Here we report the presence of localized bright areas on Ceres from an orbiting imager (8). These unusual areas are consistent with hydrated magnesium sulfates mixed with dark background material, although other compositions are possible. Of particular interest is a bright pit on the floor of crater Occator that exhibits probable sublimation of water ice, producing haze clouds inside the crater that appear and disappear with a diurnal rhythm. Slow-moving condensed-ice or dust particles (9,10) may explain this haze. We conclude that Ceres must have accreted material from beyond the 'snow line' (11), which is the distance from the Sun at which water molecules condense., We observed Ceres using the Framing Camera (FC) on board the Dawn spacecraft. The FC is equipped with a panchromatic (clear) filter and seven colour filters, covering the wavelength range [...]

Published
2015

23. Vesta's Shape and Morphology

Author

Jaumann, R., Williams, D. A., Buczkowski, D. L., Yingst, R. A., Preusker, F., Hiesinger, H., Schmedemann, N., Kneissl, T., Vincent, J. B., Blewett, D. T., Buratti, B. J., Carsenty, U., Denevi, B. W., De Sanctis, M. C., Garry, W. B., Keller, H. U., Kersten, E., Krohn, K., Li, J.-Y., Marchi, S., Matz, K. D., McCord, T. B., McSween, H. Y., Mest, S. C., Mittlefehldt, D. W., Mottola, S., Nathues, A., Neukum, G., O'Brien, D. P., Pieters, C. M., Prettyman, T. H., Raymond, C. A., Roatsch, T., Russell, C. T., Schenk, P., Schmidt, B. E., Scholten, F., Stephan, K., Sykes, M. V., Tricarico, P., Wagner, R., Zuber, M. T., and Sierks, H.

Published
2012
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25. Surface Water-Ice Deposits in the Northern Shadowed Regions of Ceres

Author

Platz, T, Nathues, A, Schorghofer, N, Preusker, F, Mazarico, E, Schroeder, S. E, Byrne, S, Kneissl, T, Schmedemann, N, Combe, J.-P, Schaefer, M, Thangjam, G. S, Hoffmann, M, Gutierrez-Marques, P, Landis, M. E, Dietrich, W, Ripken, J, Matz, K. D, and Russell, C. T

Subjects
Astronomy
Abstract

Ceres, a dwarf planet located in the main asteroid belt, has a low bulk density, and models predict that a substantial amount of water ice is present in its mantle and outer shell. The Herschel telescope and the Dawn spacecraft have observed the release of water vapor from Ceres, and exposed water ice has been detected by Dawn on its surface at mid-latitudes. Water molecules from endogenic and exogenic sources can also be cold-trapped in permanent shadows at high latitudes, as happens on the Moon and Mercury. Here we present the first image-based survey of Ceres's northern permanent shadows and report the discovery of bright deposits in cold traps. We identify a minimum of 634 permanently shadowed craters. Bright deposits are detected on the floors of just 10 of these craters in multiscattered light. We spectroscopically identify one of the bright deposits as water ice. This detection strengthens the evidence that permanently shadowed areas have preserved water ice on airless planetary bodies.

Published
2016
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31. Nature of the 'Orange' Material on Vesta From Dawn

Author

LeCorre, L, Reddy, V, Schmedemann, N, Becker, K. J, OBrien, D. P, Yamashita, N, Peplowski, P. N, Prettyman, T. H, Li, J.-Y, Coultis, E. A, Denevi, B. W, Kneissl, T, Palmer, E, Gaskell, R. W, Nathues, A, Gaffey, M. J, Mittlefeldt, D. W, Gary, W. B, Sierks, H, Russell, C. T, and Raymond, C. A

Subjects
Lunar And Planetary Science And Exploration
Abstract

From ground-based observations of Vesta, it is well-known that the vestan surface has a large variation in albedo. Analysis of images acquired by the Hubble Space Telescope allowed production of the first color maps of Vesta and showed a diverse surface in terms of reflectance. Thanks to images collected by the Dawn spacecraft at Vesta, it became obvious that these specific units observed previously can be linked to geological features. The presence of the darkest material mostly around impact craters and scattered in the Western hemisphere has been associated with carbonaceous chondrite contamination [4]; whereas the brightest materials are believed to result from exposure of unaltered material from the subsurface of Vesta (in fresh looking impact crater rims and in Rheasilvia's ejecta and rim remants). Here we focus on a distinct material characterized by a steep slope in the near-IR relative to all other kinds of materials found on Vesta. It was first detected when combining Dawn Framing Camera (FC) color images in Clementine false-color composites [5] during the Approach phase of the mission (100000 to 5200 km from Vesta). We investigate the mineralogical and elemental composition of this material and its relationship with the HEDs (Howardite-Eucrite- Diogenite group of meteorites).

Published
2014

32. Regolith Depth, Mobility, and Variability on Vesta from Dawn's Low Altitude Mapping Orbit

Author

Denevi, B. W, Coman, E. I, Blewett, D. T, Mittlefehldt, D. W, Buczkowski, D. L, Combe, J.-P, De Sanctis, M. C, Jaumann, R, Li, J.-Y, Marchi, S, Nathues, A, Petro, N. E, Pieters, C. M, Schenk. P, Schmedemann, N, Schroeder, S, Sunshine, J. M, Williams, D. A, Raymond, C. A, and Russell, C. T

Subjects
Space Sciences (General)
Abstract

Regolith, the fragmental debris layer formed from impact events of all sizes, covers the surface of all asteroids imaged by spacecraft to date. Here we use Framing Camera (FC) images [1] acquired by the Dawn spacecraft [2] from its low-altitude mapping orbit (LAMO) of 210 km (pixel scales of ~20 m) to characterize regolith depth, variability, and mobility on Vesta, and to locate areas of especially thin regolith and exposures of competent material. These results will help to evaluate how the surface of this differentiated asteroid has evolved over time, and provide key contextual information for understanding the origin and degree of mixing of the surficial materials for which compositions are estimated [3,4] and the causes of the relative spectral immaturity of the surface [5]. Vestan regolith samples, in the form of howardite meteorites, can be studied in the laboratory to provide complementary constraints on the regolith process [6].

Published
2012

33. The Saricicek howardite fall in Turkey : Source crater of HED meteorites on Vesta and impact risk of Vestoids

Author

Unsalan O., Jenniskens P., Yin Q.-Z., Kaygisiz E., Albers J., Clark D.L., Granvik M., Demirkol I., Erdogan I.Y., Bengu A.S., Özel M.E., Terzioglu Z., Gi N., Brown P., Yalcinkaya E., Temel T., Prabhu D.K., Robertson D.K., Boslough M., Ostrowski D.R., Kimberley J., Er S., Rowland D.J., Bryson K.L., Altunayar-Unsalan C., Ranguelov B., Karamanov A., Tatchev D., Kocahan Ö., Oshtrakh M.I., Maksimova A.A., Karabanalov M.S., Verosub K.L., Levin E., Uysal I., Hoffmann V., Hiroi T., Reddy V., Ildiz G.O., Bolukbasi O., Zolensky M.E., Hochleitner R., Kaliwoda M., Öngen S., Fausto R., Nogueira B.A., Chukin A.V., Karashanova D., Semionkin V.A., Yeşiltaş M., Glotch T., Yilmaz A., Friedrich J.M., Sanborn M.E., Huyskens M., Ziegler K., Williams C.D., Schönbächler M., Bauer K., Meier M.M.M., Maden C., Busemann H., Welten K.C., Caffee M.W., Laubenstein M., Zhou Q., Li Q.-L., Li X.-H., Liu Y., Tang G.-Q., Sears D.W.G., Mclain H.L., Dworkin J.P., Elsila J.E., Glavin D.P., Schmitt-Kopplin P., Ruf A., LE Corre L., Schmedemann N., (The Saricicek Meteorite Consortium), Particle Physics and Astrophysics, Planetary-system research, and Ege Üniversitesi

Subjects
Howardite, Geochemistry, Oxygen-Isotope, 010502 geochemistry & geophysics, 01 natural sciences, Collisional History, 114 Physical sciences, U-Pb Analysis, ASTEROID VESTA, Impact crater, 0103 physical sciences, Isotopic Composition, THERMAL HISTORY, ISOTOPIC COMPOSITION, Asteroid Vesta, 010303 astronomy & astrophysics, Cosmogenic Nuclides, PRODUCTION-RATES, COLLISIONAL HISTORY, 0105 earth and related environmental sciences, PARENT BODY, Meteoroid, Thermal History, COSMOGENIC NUCLIDES, EXPOSURE HISTORY, Asteroid family, 115 Astronomy, Space science, Regolith, U-PB ANALYSIS, OXYGEN-ISOTOPE, Geophysics, Meteorite, 13. Climate action, Space and Planetary Science, Asteroid, Carbonaceous chondrite, Production-Rates, Exposure History, Parent Body, Geology, Astrophysics - Earth and Planetary Astrophysics
Abstract

EgeUn###, The Sariçiçek howardite meteorite shower consisting of 343 documented stones occurred on September 2, 2015 in Turkey and is the first documented howardite fall. Cosmogenic isotopes show that Sariçiçek experienced a complex cosmic-ray exposure history, exposed during ~12–14 Ma in a regolith near the surface of a parent asteroid, and that an ~1 m sized meteoroid was launched by an impact 22 ± 2 Ma ago to Earth (as did one-third of all HED meteorites). SIMS dating of zircon and baddeleyite yielded 4550.4 ± 2.5 Ma and 4553 ± 8.8 Ma crystallization ages for the basaltic magma clasts. The apatite U-Pb age of 4525 ± 17 Ma, K-Ar age of ~3.9 Ga, and the U,Th-He ages of 1.8 ± 0.7 and 2.6 ± 0.3 Ga are interpreted to represent thermal metamorphic and impact-related resetting ages, respectively. Petrographic; geochemical; and O-, Cr-, and Ti-isotopic studies confirm that Sariçiçek belongs to the normal clan of HED meteorites. Petrographic observations and analysis of organic material indicate a small portion of carbonaceous chondrite material in the Sariçiçek regolith and organic contamination of the meteorite after a few days on soil. Video observations of the fall show an atmospheric entry at 17.3 ± 0.8 km s -1 from NW; fragmentations at 37, 33, 31, and 27 km altitude; and provide a pre-atmospheric orbit that is the first dynamical link between the normal HED meteorite clan and the inner Main Belt. Spectral data indicate the similarity of Sariçiçek with the Vesta asteroid family (V-class) spectra, a group of asteroids stretching to delivery resonances, which includes (4) Vesta. Dynamical modeling of meteoroid delivery to Earth shows that the complete disruption of a ~1 km sized Vesta family asteroid or a ~10 km sized impact crater on Vesta is required to provide sufficient meteoroids ?4 m in size to account for the influx of meteorites from this HED clan. The 16.7 km diameter Antionia impact crater on Vesta was formed on terrain of the same age as given by the 4 He retention age of Sariçiçek. Lunar scaling for crater production to crater counts of its ejecta blanket show it was formed ~22 Ma ago. © The Meteoritical Society, 2019., 58261, 40339 nccr – on the move NNX14AM62G MFAG/113F035 Simons Foundation: 302497 NNX14-AR92G, NNX16AD34G Academy of Finland: 299543 Government Council on Grants, Russian Federation: ? 02., A03.21.0006 Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung: PZ00P2_154874 Ministry of Education and Science of the Russian Federation: 3.1959.2017/4.6 National Natural Science Foundation of China: 41403055, Acknowledgments—We thank N. Ergu€n and family in the village of Sari©ci©cek for donating the meteorites studied here and collecting meteorite fall coordinates. We thank E. Atalan and S. Ozdemir€ at Bingo€l University, and E. Necip Yardım and M. C© i©cek at Mu©s Alparslan University, for facilitating our research at the campuses, and S. Pamuk at the Bingo€l police headquarters. We thank A. and T. Ozdum€ an, police officers in Bingo€l, for assisting with the field study. For technical assistance, we further acknowledge support from M. Fehr, Y.-J. Lai, and L. Hoffland (NASA Ames Research Center); David Mittlefehldt (NASA JSC); K. Wimmer (Ries Crater Museum); J. Sanchez (Planetary Science Institute); A. Neesemann (Free University Berlin); S. Atanasova-Vladimirova and I. Piroeva (Institute of Physical Chemistry, BAS); and B. Georgieva and V. Strijkova (Institute of Optical Materials and Technologies, BAS). This work was supported by Istanbul University (Project No. 40339 and 58261), the Scientific and Technological Research Council of Turkey (MFAG/113F035), the Swiss National Science foundation (PZ00P2_154874 and NCCR PlanetS), the Ministry of Science and Higher Education of the Russian Federation (Project # 3.1959.2017/4.6), Act 211 of the Government of the Russian Federation, contract ? 02.A03.21.0006, the National Natural Science Foundation of China (41403055), the Simons Foundation (302497), the Academy of Finland (299543), the NASA Cosmochemistry Program (NNX14AM62G), the NASA Emerging Worlds Program (NNX16AD34G), and the NASA NEOO program (NNX14-AR92G).

Published
2019

34. Ray Craters on Ganymede as Time-Stratigraphic Markers

Author

Wagner, Roland, Schmedemann, N., Werner, S. C., Head, J W, Stephan, Katrin, Krohn, Katrin, Jaumann, R, Roatsch, Thomas, Hoffmann, Harald, and Palumbo, P.

Subjects
Oberflächenalter, Ganymed, Stratigraphie
Published
2019

35. The Sariçiçek howardite fall in Turkey: Source crater of HED meteorites on Vesta and impact risk of Vestoids

Author

Unsalan, O., Jenniskens, P., Yin, Q. -Z., Kaygisiz, E., Albers, J., Clark, D. L., Granvik, M., Demirkol, I., Erdogan, I. Y., Bengu, A. S., Özel, M. E., Terzioglu, Z., Gi, N., Brown, P., Yalcinkaya, E., Temel, T., Prabhu, D. K., Robertson, D. K., Boslough, M., Ostrowski, D. R., Kimberley, J., Er, S., Rowland, D. J., Bryson, K. L., Altunayar-Unsalan, C., Ranguelov, B., Karamanov, A., Tatchev, D., Kocahan, Ö., Oshtrakh, M. I., Maksimova, A. A., Karabanalov, M. S., Verosub, K. L., Levin, E., Uysal, I., Hoffmann, V., Hiroi, T., Reddy, V., Ildiz, G. O., Bolukbasi, O., Zolensky, M. E., Hochleitner, R., Kaliwoda, M., Öngen, S., Fausto, R., Nogueira, B. A., Chukin, A. V., Karashanova, D., Semionkin, V. A., Yeşiltaş, M., Glotch, T., Yilmaz, A., Friedrich, J. M., Sanborn, M. E., Huyskens, M., Ziegler, K., Williams, C. D., Schönbächler, M., Bauer, K., Meier, M. M. M., Maden, C., Busemann, H., Welten, K. C., Caffee, M. W., Laubenstein, M., Zhou, Q., Li, Q. -L., Li, X. -H., Liu, Y., Tang, G. -Q., Sears, D. W. G., Mclain, H. L., Dworkin, J. P., Elsila, J. E., Glavin, D. P., Schmitt-Kopplin, P., Ruf, A., LE, Corre, L., Schmedemann, N., Unsalan, O., Jenniskens, P., Yin, Q. -Z., Kaygisiz, E., Albers, J., Clark, D. L., Granvik, M., Demirkol, I., Erdogan, I. Y., Bengu, A. S., Özel, M. E., Terzioglu, Z., Gi, N., Brown, P., Yalcinkaya, E., Temel, T., Prabhu, D. K., Robertson, D. K., Boslough, M., Ostrowski, D. R., Kimberley, J., Er, S., Rowland, D. J., Bryson, K. L., Altunayar-Unsalan, C., Ranguelov, B., Karamanov, A., Tatchev, D., Kocahan, Ö., Oshtrakh, M. I., Maksimova, A. A., Karabanalov, M. S., Verosub, K. L., Levin, E., Uysal, I., Hoffmann, V., Hiroi, T., Reddy, V., Ildiz, G. O., Bolukbasi, O., Zolensky, M. E., Hochleitner, R., Kaliwoda, M., Öngen, S., Fausto, R., Nogueira, B. A., Chukin, A. V., Karashanova, D., Semionkin, V. A., Yeşiltaş, M., Glotch, T., Yilmaz, A., Friedrich, J. M., Sanborn, M. E., Huyskens, M., Ziegler, K., Williams, C. D., Schönbächler, M., Bauer, K., Meier, M. M. M., Maden, C., Busemann, H., Welten, K. C., Caffee, M. W., Laubenstein, M., Zhou, Q., Li, Q. -L., Li, X. -H., Liu, Y., Tang, G. -Q., Sears, D. W. G., Mclain, H. L., Dworkin, J. P., Elsila, J. E., Glavin, D. P., Schmitt-Kopplin, P., Ruf, A., LE, Corre, L., and Schmedemann, N.

Abstract

The Sariçiçek howardite meteorite shower consisting of 343 documented stones occurred on September 2, 2015 in Turkey and is the first documented howardite fall. Cosmogenic isotopes show that Sariçiçek experienced a complex cosmic-ray exposure history, exposed during ~12–14 Ma in a regolith near the surface of a parent asteroid, and that an ~1 m sized meteoroid was launched by an impact 22 ± 2 Ma ago to Earth (as did one-third of all HED meteorites). SIMS dating of zircon and baddeleyite yielded 4550.4 ± 2.5 Ma and 4553 ± 8.8 Ma crystallization ages for the basaltic magma clasts. The apatite U-Pb age of 4525 ± 17 Ma, K-Ar age of ~3.9 Ga, and the U,Th-He ages of 1.8 ± 0.7 and 2.6 ± 0.3 Ga are interpreted to represent thermal metamorphic and impact-related resetting ages, respectively. Petrographic; geochemical; and O-, Cr-, and Ti-isotopic studies confirm that Sariçiçek belongs to the normal clan of HED meteorites. Petrographic observations and analysis of organic material indicate a small portion of carbonaceous chondrite material in the Sariçiçek regolith and organic contamination of the meteorite after a few days on soil. Video observations of the fall show an atmospheric entry at 17.3 ± 0.8 km s −1 from NW; fragmentations at 37, 33, 31, and 27 km altitude; and provide a pre-atmospheric orbit that is the first dynamical link between the normal HED meteorite clan and the inner Main Belt. Spectral data indicate the similarity of Sariçiçek with the Vesta asteroid family (V-class) spectra, a group of asteroids stretching to delivery resonances, which includes (4) Vesta. Dynamical modeling of meteoroid delivery to Earth shows that the complete disruption of a ~1 km sized Vesta family asteroid or a ~10 km sized impact crater on Vesta is required to provide sufficient meteoroids ≤4 m in size to account for the influx of meteorites from this HED clan. The 16.7 km diameter Antionia impact crater on Vesta was formed on terrain of the same age as given by the 4 He retention a

Published
2019

39. Ceres’ impact craters – Relationships between surface composition and geology

Author

Stephan, K., primary, Jaumann, R., additional, Zambon, F., additional, Carrozzo, F.G., additional, Wagner, R., additional, Longobardo, A., additional, Palomba, E., additional, De Sanctis, M.C., additional, Tosi, F., additional, Ammannito, E., additional, Combe, J.-P., additional, Mc Fadden, L.A., additional, Krohn, K., additional, Schulzeck, F., additional, von der Gathen, I., additional, Williams, D.A., additional, Scully, J.E.C., additional, Schmedemann, N., additional, Neesemann, A., additional, Roatsch, T., additional, Matz, K.-D., additional, Preusker, F., additional, Raymond, C.A., additional, and Russell, C.T., additional

Published
2019
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40. Ceres’ Ezinu quadrangle: a heavily cratered region with evidence for localized subsurface water ice and the context of Occator crater

Author

Scully, Jennifer E.C., primary, Buczkowski, D.L., additional, Neesemann, A., additional, Williams, D.A., additional, Mest, S.C., additional, Raymond, C.A., additional, Nass, A., additional, Hughson, K.H.G., additional, Kneissl, T., additional, Pasckert, J.H., additional, Ruesch, O., additional, Frigeri, A., additional, Marchi, S., additional, Combe, J-P., additional, Schmedemann, N., additional, Schmidt, B.E., additional, Chilton, H.T., additional, Russell, C.T., additional, Jaumann, R., additional, Preusker, F., additional, Roatsch, T., additional, Hoffmann, M., additional, Nathues, A., additional, Schaefer, M., additional, and Ermakov, A.I., additional

Published
2018
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41. Geologic mapping of the Ac-2 Coniraya quadrangle of Ceres from NASA's Dawn mission: Implications for a heterogeneously composed crust

Author

Pasckert, J.H., primary, Hiesinger, H., additional, Ruesch, O., additional, Williams, D.A., additional, Naß, A., additional, Kneissl, T., additional, Mest, S.C., additional, Buczkowski, D.L., additional, Scully, J.E.C., additional, Schmedemann, N., additional, Jaumann, R., additional, Roatsch, T., additional, Preusker, F., additional, Nathues, A., additional, Hoffmann, M., additional, Schäfer, M., additional, De Sanctis, M.C., additional, Raymond, C.A., additional, and Russell, C.T., additional

Published
2018
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42. Geological mapping of the Ac-10 Rongo Quadrangle of Ceres

Author

Platz, T., primary, Nathues, A., additional, Sizemore, H.G., additional, Crown, D.A., additional, Hoffmann, M., additional, Schäfer, M., additional, Schmedemann, N., additional, Kneissl, T., additional, Neesemann, A., additional, Mest, S.C., additional, Buczkowski, D.L., additional, Ruesch, O., additional, Hughson, K.H.G., additional, Naß, A., additional, Williams, D.A., additional, and Preusker, F., additional

Published
2018
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43. The geology of the Kerwan quadrangle of dwarf planet Ceres: Investigating Ceres’ oldest, largest impact basin

Author

Williams, David A., primary, Kneissl, T., additional, Neesemann, A., additional, Mest, S.C., additional, Palomba, E., additional, Platz, T., additional, Nathues, A., additional, Longobardo, A., additional, Scully, J.E.C., additional, Ermakov, A., additional, Jaumann, R., additional, Buczkowski, D.L., additional, Schäfer, M., additional, Thangjam, G., additional, Pieters, C.M., additional, Roatsch, T., additional, Preusker, F., additional, Marchi, S., additional, Schmedemann, N., additional, Hiesinger, H., additional, Frigeri, A., additional, Raymond, C.A., additional, and Russell, C.T., additional

Published
2018
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44. Geologic mapping of the Ac-11 Sintana quadrangle: Assessing diverse crater morphologies

Author

Schulzeck, F., primary, Krohn, K., additional, v.d. Gathen, I., additional, Schmedemann, N., additional, Stephan, K., additional, Jaumann, R., additional, Williams, D.A., additional, Wagner, R., additional, Buczkowski, D.L., additional, Mest, S.C., additional, Scully, J.E.C., additional, Kersten, E., additional, Matz, K.-D., additional, Naß, A., additional, Preusker, F., additional, Roatsch, T., additional, Raymond, C.A., additional, and Russell, C.T., additional

Published
2018
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45. Geological Mapping of the Ac-10 Rongo Quadrangle of Ceres

Author

Platz, T., Nathues, A., Sizemore, H., Crown, D.A., Hoffmann, M., Schäfer, M., Schmedemann, N., Kneissl, T., Neesemann, Adrian, Mest, S., Buczkowski, D.L., Ruesch, O., Naß, Andrea, Williams, David A., and Preusker, Frank

Subjects
Rongo, Ceres, Geological Mapping
Published
2017

47. Crater-related cryovolcanism on Ceres

Author

Krohn, Katrin, Jaumann, R., Stephan, Katrin, Otto, Katharina A., Schmedemann, N., Wagner, Roland, Matz, Klaus-Dieter, Tosi, F., Zambon, F., von der Gathen, Isabel, Schulzeck, Franziska, Pieters, C.M., Roatsch, Thomas, Raymond, C.A., and Russell, C.T.

Subjects
asteroids, Planetengeologie, Asteroiden und Kometen, crater, cryovolcanism, Ceres
Abstract

During the Dawn mission, observations at Ceres reveal numerous interesting post-impact modifications in and around craters. These modifications contain the deposition of extended plains material with pits, multiple lobate flows, and widely dispersed deposits that form a diffuse veneer on the preexisting surface.

Published
2017

48. Geomorpholohy and Topography of the Interior of Occator Crater on Ceres

Author

Jaumann, R., Preusker, Frank, Krohn, Katrin, von der Gathen, Isabel, Stephan, K., Matz, Klaus-Dieter, Elgner, Stephan, Otto, K., Schmedemann, N., Neesemann, Adrian, Roatsch, Thomas, Kersten, Elke, Schroeder, S, Schulzeck, Franziska, Tosi, F., Sanctis, Maria Cristina De, Buczkowski, D.L., Scully, J.E.C., Hiesinger, H., Raymond, C.A., Russell, C.T., Stein, N.T., Williams, D.A., Ruesch, O., and Schenk, P.

Subjects
Planetengeologie, Asteroiden und Kometen, Planetengeodäsie, Ceres
Abstract

Geomorpholohy and Topography of the Interior of Occator Crater on Ceres

Published
2017

49. Topography and Geomorphology of the Interior of Occator Crater on Ceres

Author

Jaumann, Ralf, Preusker, Frank, Krohn, Katrin, von der Gathen, Isabel, Stephan, Katrin, Matz, Klaus-Dieter, Elgner, Stephan, Otto, Katharina A., Schmedemann, N., Neesemann, Adrian, Roatsch, Thomas, Kersten, Elke, Schroeder, S, Schulzeck, Franziska, Tosi, F., Desanctis, M.C., Buczkowski, D.L., Scully, J.E.C., Hiesinger, H., Raymond, C.A., Russell, C.T., Stein, N. T., Williams, D.A., Ruesch, O., and Schenk, P.

Subjects
topography, morphology, Ceres, DAWN
Published
2017

50. An investigation of the bluish material on Ceres

Author

Stephan, K., Jaumann, Ralf, Krohn, Katrin, Schmedemann, N., Zambon, F., Tosi, F., Carrozzo, F. G., McFadden, L.A., Otto, Katharina A., De Sanctis, M.C., Ammannito, E., Matz, Klaus-Dieter, Roatsch, Thomas, Preusker, Frank, Raymond, C.A., and Russell, C.T.

Subjects
Dawn mission, asteroids, geology, Ceres, surface composition, impacts
Abstract

The dwarf planet Ceres shows spatially well-defined regions, which exhibit a negative (blue) spectral slope between 0.5 and 2.5 µm. Comparisons with planetary bodies known to exhibit a blue slope and spectral properties of materials identified on Ceres's surface based on infrared wavelength signatures indicate that the spectral changes could be related to physical properties of the surface material rather than variations in its composition. The close association of bluish surface regions to fresh impact craters implies a possible relationship to an impact-triggered alteration and/or space weathering processes. The bluish regions could be linked with blankets of ultrafine grains and partly amorphous phyllosilicates, which form larger agglomerates due to the sticky behavior of impact-induced phyllosilicate dust and/or the amorphization of the ejecta material during the impact process. Space weathering processes (micrometeoritic impacts, temperature changes) cause a reversal of the agglutination process and a recrystallization of the surface material with time resulting in a reddening of the spectral slope.

Published
2017

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