ALBERT

Description: Bright carbonate deposits as evidence of aqueous alteration on (1) Ceres Nature 536, 7614 (2016). doi:10.1038/nature18290 Authors: M. C. De Sanctis, A. Raponi, E. Ammannito, M. Ciarniello, M. J. Toplis, H. Y. McSween, J. C. Castillo-Rogez, B. L. Ehlmann, F. G. Carrozzo, S. Marchi, F. Tosi, F. Zambon, F. Capaccioni, M. T. Capria, S. Fonte, M. Formisano, A. Frigeri, M. Giardino, A. Longobardo, G. Magni, E. Palomba, L. A. McFadden, C. M. Pieters, R. Jaumann, P. Schenk, R. Mugnuolo, C. A. Raymond & C. T. Russell The typically dark surface of the dwarf planet Ceres is punctuated by areas of much higher albedo, most prominently in the Occator crater. These small bright areas have been tentatively interpreted as containing a large amount of hydrated magnesium sulfate, in contrast to the average surface, which is a mixture of low-albedo materials and magnesium phyllosilicates, ammoniated phyllosilicates and carbonates. Here we report high spatial and spectral resolution near-infrared observations of the bright areas in the Occator crater on Ceres. Spectra of these bright areas are consistent with a large amount of sodium carbonate, constituting the most concentrated known extraterrestrial occurrence of carbonate on kilometre-wide scales in the Solar System. The carbonates are mixed with a dark component and small amounts of phyllosilicates, as well as ammonium carbonate or ammonium chloride. Some of these compounds have also been detected in the plume of Saturn’s sixth-largest moon Enceladus. The compounds are endogenous and we propose that they are the solid residue of crystallization of brines and entrained altered solids that reached the surface from below. The heat source may have been transient (triggered by impact heating). Alternatively, internal temperatures may be above the eutectic temperature of subsurface brines, in which case fluids may exist at depth on Ceres today.

Description: Abstract Thermal inertia is a key information to quantify the physical status of a planetary surface. We derive the thermal inertia of the surface of Ceres using spatially‐resolved data from the Dawn mission. For each location, this quantity can be constrained by comparing theoretical and observed diurnal temperature profiles from retrieved temperatures. We calculated Ceres’ surface theoretical temperatures with a thermophysical model that provides temperature as a function of thermal conductivity and roughness, and we determined the values of those parameters for which the best fit with the observed data is obtained. Our results suggest that the area of crater Haulani displays thermal inertia values (up to 130‐140 Jm−2 s−½ K−1) substantially higher than the very low to low values (from 1‐15 to 50‐60 Jm−2 s−½ K−1) derived for the overall surface of Ceres. The results are more ambiguous for the bright faculae located in the floor of crater Occator.

Description: [1]  The first ever regional thermal properties map of Vesta has been derived from the temperatures retrieved by infrared data by the mission Dawn. The low average value of thermal inertia, 30 ± 10 Jm −2  s −0.5  K −1 , indicates a surface covered by a fine regolith. A range of thermal inertia values suggesting terrains with different physical properties has been determined. The lower thermal inertia of the regions north of the equator suggests that they are covered by an older, more processed surface. A few specific areas have higher than average thermal inertia values, indicative of a more compact material. The highest thermal inertia value has been determined on the Marcia crater, known for its pitted terrain and the presence of hydroxyl in the ejecta. Our results suggest that this type of terrain can be the result of soil compaction following the degassing of a local subsurface reservoir of volatiles.

Description: Studies of the dwarf planet (1) Ceres using ground-based and orbiting telescopes have concluded that its closest meteoritic analogues are the volatile-rich CI and CM carbonaceous chondrites. Water in clay minerals, ammoniated phyllosilicates, or a mixture of Mg(OH)2 (brucite), Mg2CO3 and iron-rich serpentine have all been proposed to exist on the surface. In particular, brucite has been suggested from analysis of the mid-infrared spectrum of Ceres. But the lack of spectral data across telluric absorption bands in the wavelength region 2.5 to 2.9 micrometres--where the OH stretching vibration and the H2O bending overtone are found--has precluded definitive identifications. In addition, water vapour around Ceres has recently been reported, possibly originating from localized sources. Here we report spectra of Ceres from 0.4 to 5 micrometres acquired at distances from ~82,000 to 4,300 kilometres from the surface. Our measurements indicate widespread ammoniated phyllosilicates across the surface, but no detectable water ice. Ammonia, accreted either as organic matter or as ice, may have reacted with phyllosilicates on Ceres during differentiation. This suggests that material from the outer Solar System was incorporated into Ceres, either during its formation at great heliocentric distance or by incorporation of material transported into the main asteroid belt.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉De Sanctis, M C -- Ammannito, E -- Raponi, A -- Marchi, S -- McCord, T B -- McSween, H Y -- Capaccioni, F -- Capria, M T -- Carrozzo, F G -- Ciarniello, M -- Longobardo, A -- Tosi, F -- Fonte, S -- Formisano, M -- Frigeri, A -- Giardino, M -- Magni, G -- Palomba, E -- Turrini, D -- Zambon, F -- Combe, J-P -- Feldman, W -- Jaumann, R -- McFadden, L A -- Pieters, C M -- Prettyman, T -- Toplis, M -- Raymond, C A -- Russell, C T -- England -- Nature. 2015 Dec 10;528(7581):241-4. doi: 10.1038/nature16172.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Istituto di Astrofisica e Planetologia Spaziali, INAF, Via del Fosso del Cavaliere 100, 00133 Roma, Italy. ; Institute of Geophysics and Planetary Physics, University of California, Los Angeles, California 90095-1567, USA. ; Southwest Research Institute, 1050 Walnut Street, Boulder, Colorado 80302, USA. ; Bear Fight Institute, 22 Fiddler's Road, PO Box 667, Winthrop, Washington 98862, USA. ; Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, Tennessee 37996-1410, USA. ; Planetary Science Institute, Tucson, Arizona 85719-2395, USA. ; Institute of Planetary Research, German Aerospace Center (DLR), Rutherfordstrasse 2, 12489 Berlin, Germany. ; NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA. ; Department of Earth, Environmental, and Planetary Sciences, Brown University, Providence, Rhode Island 02912, USA. ; Institut de Recherche d'Astrophysique et Planetologie, Observatoire Midi Pyrenees, Universite Paul Sabatier, 14 Avenue E. Belin, 31400 Toulouse, France. ; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26659184" target="_blank"〉PubMed〈/a〉

Description: The mineralogy of Vesta, based on data obtained by the Dawn spacecraft's visible and infrared spectrometer, is consistent with howardite-eucrite-diogenite meteorites. There are considerable regional and local variations across the asteroid: Spectrally distinct regions include the south-polar Rheasilvia basin, which displays a higher diogenitic component, and equatorial regions, which show a higher eucritic component. The lithologic distribution indicates a deeper diogenitic crust, exposed after excavation by the impact that formed Rheasilvia, and an upper eucritic crust. Evidence for mineralogical stratigraphic layering is observed on crater walls and in ejecta. This is broadly consistent with magma-ocean models, but spectral variability highlights local variations, which suggests that the crust can be a complex assemblage of eucritic basalts and pyroxene cumulates. Overall, Vesta mineralogy indicates a complex magmatic evolution that led to a differentiated crust and mantle.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉De Sanctis, M C -- Ammannito, E -- Capria, M T -- Tosi, F -- Capaccioni, F -- Zambon, F -- Carraro, F -- Fonte, S -- Frigeri, A -- Jaumann, R -- Magni, G -- Marchi, S -- McCord, T B -- McFadden, L A -- McSween, H Y -- Mittlefehldt, D W -- Nathues, A -- Palomba, E -- Pieters, C M -- Raymond, C A -- Russell, C T -- Toplis, M J -- Turrini, D -- New York, N.Y. -- Science. 2012 May 11;336(6082):697-700. doi: 10.1126/science.1219270.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Istituto di Astrofisica e Planetologia Spaziali, Istituto Nazionale di Astrofisica, Rome, Italy. mariacristina.desanctis@iaps.inaf.it〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22582257" target="_blank"〉PubMed〈/a〉

Description: Olivine is a major component of the mantle of differentiated bodies, including Earth. Howardite, eucrite and diogenite (HED) meteorites represent regolith, basaltic-crust, lower-crust and possibly ultramafic-mantle samples of asteroid Vesta, which is the lone surviving, large, differentiated, basaltic rocky protoplanet in the Solar System. Only a few of these meteorites, the orthopyroxene-rich diogenites, contain olivine, typically with a concentration of less than 25 per cent by volume. Olivine was tentatively identified on Vesta, on the basis of spectral and colour data, but other observations did not confirm its presence. Here we report that olivine is indeed present locally on Vesta's surface but that, unexpectedly, it has not been found within the deep, south-pole basins, which are thought to be excavated mantle rocks. Instead, it occurs as near-surface materials in the northern hemisphere. Unlike the meteorites, the olivine-rich (more than 50 per cent by volume) material is not associated with diogenite but seems to be mixed with howardite, the most common surface material. Olivine is exposed in crater walls and in ejecta scattered diffusely over a broad area. The size of the olivine exposures and the absence of associated diogenite favour a mantle source, but the exposures are located far from the deep impact basins. The amount and distribution of observed olivine-rich material suggest a complex evolutionary history for Vesta.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ammannito, E -- De Sanctis, M C -- Palomba, E -- Longobardo, A -- Mittlefehldt, D W -- McSween, H Y -- Marchi, S -- Capria, M T -- Capaccioni, F -- Frigeri, A -- Pieters, C M -- Ruesch, O -- Tosi, F -- Zambon, F -- Carraro, F -- Fonte, S -- Hiesinger, H -- Magni, G -- McFadden, L A -- Raymond, C A -- Russell, C T -- Sunshine, J M -- England -- Nature. 2013 Dec 5;504(7478):122-5. doi: 10.1038/nature12665. Epub 2013 Nov 6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Istituto di Astrofisica e Planetologia Spaziali, INAF, 00133 Rome, Italy.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24196707" target="_blank"〉PubMed〈/a〉

Description: Localized dark and bright materials, often with extremely different albedos, were recently found on Vesta's surface. The range of albedos is among the largest observed on Solar System rocky bodies. These dark materials, often associated with craters, appear in ejecta and crater walls, and their pyroxene absorption strengths are correlated with material brightness. It was tentatively suggested that the dark material on Vesta could be either exogenic, from carbon-rich, low-velocity impactors, or endogenic, from freshly exposed mafic material or impact melt, created or exposed by impacts. Here we report Vesta spectra and images and use them to derive and interpret the properties of the 'pure' dark and bright materials. We argue that the dark material is mainly from infall of hydrated carbonaceous material (like that found in a major class of meteorites and some comet surfaces), whereas the bright material is the uncontaminated indigenous Vesta basaltic soil. Dark material from low-albedo impactors is diffused over time through the Vestan regolith by impact mixing, creating broader, diffuse darker regions and finally Vesta's background surface material. This is consistent with howardite-eucrite-diogenite meteorites coming from Vesta.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉McCord, T B -- Li, J-Y -- Combe, J-P -- McSween, H Y -- Jaumann, R -- Reddy, V -- Tosi, F -- Williams, D A -- Blewett, D T -- Turrini, D -- Palomba, E -- Pieters, C M -- De Sanctis, M C -- Ammannito, E -- Capria, M T -- Le Corre, L -- Longobardo, A -- Nathues, A -- Mittlefehldt, D W -- Schroder, S E -- Hiesinger, H -- Beck, A W -- Capaccioni, F -- Carsenty, U -- Keller, H U -- Denevi, B W -- Sunshine, J M -- Raymond, C A -- Russell, C T -- England -- Nature. 2012 Nov 1;491(7422):83-6. doi: 10.1038/nature11561.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Bear Fight Institute, 22 Fiddler's Road, Box 667, Winthrop, Washington 98862, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/23128228" target="_blank"〉PubMed〈/a〉

Description: Critical measurements for understanding accretion and the dust/gas ratio in the solar nebula, where planets were forming 4.5 billion years ago, are being obtained by the GIADA (Grain Impact Analyser and Dust Accumulator) experiment on the European Space Agency's Rosetta spacecraft orbiting comet 67P/Churyumov-Gerasimenko. Between 3.6 and 3.4 astronomical units inbound, GIADA and OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System) detected 35 outflowing grains of mass 10(-10) to 10(-7) kilograms, and 48 grains of mass 10(-5) to 10(-2) kilograms, respectively. Combined with gas data from the MIRO (Microwave Instrument for the Rosetta Orbiter) and ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) instruments, we find a dust/gas mass ratio of 4 +/- 2 averaged over the sunlit nucleus surface. A cloud of larger grains also encircles the nucleus in bound orbits from the previous perihelion. The largest orbiting clumps are meter-sized, confirming the dust/gas ratio of 3 inferred at perihelion from models of dust comae and trails.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Rotundi, Alessandra -- Sierks, Holger -- Della Corte, Vincenzo -- Fulle, Marco -- Gutierrez, Pedro J -- Lara, Luisa -- Barbieri, Cesare -- Lamy, Philippe L -- Rodrigo, Rafael -- Koschny, Detlef -- Rickman, Hans -- Keller, Horst Uwe -- Lopez-Moreno, Jose J -- Accolla, Mario -- Agarwal, Jessica -- A'Hearn, Michael F -- Altobelli, Nicolas -- Angrilli, Francesco -- Barucci, M Antonietta -- Bertaux, Jean-Loup -- Bertini, Ivano -- Bodewits, Dennis -- Bussoletti, Ezio -- Colangeli, Luigi -- Cosi, Massimo -- Cremonese, Gabriele -- Crifo, Jean-Francois -- Da Deppo, Vania -- Davidsson, Bjorn -- Debei, Stefano -- De Cecco, Mariolino -- Esposito, Francesca -- Ferrari, Marco -- Fornasier, Sonia -- Giovane, Frank -- Gustafson, Bo -- Green, Simon F -- Groussin, Olivier -- Grun, Eberhard -- Guttler, Carsten -- Herranz, Miguel L -- Hviid, Stubbe F -- Ip, Wing -- Ivanovski, Stavro -- Jeronimo, Jose M -- Jorda, Laurent -- Knollenberg, Joerg -- Kramm, Rainer -- Kuhrt, Ekkehard -- Kuppers, Michael -- Lazzarin, Monica -- Leese, Mark R -- Lopez-Jimenez, Antonio C -- Lucarelli, Francesca -- Lowry, Stephen C -- Marzari, Francesco -- Epifani, Elena Mazzotta -- McDonnell, J Anthony M -- Mennella, Vito -- Michalik, Harald -- Molina, Antonio -- Morales, Rafael -- Moreno, Fernando -- Mottola, Stefano -- Naletto, Giampiero -- Oklay, Nilda -- Ortiz, Jose L -- Palomba, Ernesto -- Palumbo, Pasquale -- Perrin, Jean-Marie -- Rodriguez, Julio -- Sabau, Lola -- Snodgrass, Colin -- Sordini, Roberto -- Thomas, Nicolas -- Tubiana, Cecilia -- Vincent, Jean-Baptiste -- Weissman, Paul -- Wenzel, Klaus-Peter -- Zakharov, Vladimir -- Zarnecki, John C -- New York, N.Y. -- Science. 2015 Jan 23;347(6220):aaa3905. doi: 10.1126/science.aaa3905.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Istituto di Astrofisica e Planetologia Spaziali, Istituto Nazionale di Astrofisica (INAF), Via Fosso del Cavaliere, 100, 0133 Rome, Italy. Universita degli Studi di Napoli "Parthenope," Dipartimento di Scienze e Tecnologie, CDN IC4, 80143 Naples, Italy. rotundi@uniparthenope.it. ; Max-Planck-Institut fur Sonnensystemforschung, Justus-von-Liebig-Weg, 3, 37077 Gottingen, Germany. ; Istituto di Astrofisica e Planetologia Spaziali, Istituto Nazionale di Astrofisica (INAF), Via Fosso del Cavaliere, 100, 0133 Rome, Italy. ; Osservatorio Astronomico, INAF, Via Tiepolo 11, 34143 Trieste, Italy. ; Instituto de Astrofisica de Andalucia, Consejo Superior de Investigaciones Cientificas (CSIC), P.O. Box 3008, 18080 Granada, Spain. ; Department of Physics and Astronomy, Padova University, Vicolo dell'Osservatorio 3, 35122 Padova, Italy. ; Laboratoire d'Astrophysique de Marseille, UMR 7326, CNRS and Aix-Marseille Universite, 13388 Marseille, France. ; Centro de Astrobiologia (Instituto Nacional de Tecnica Aerospacial-CSIC), 28691 Villanueva de la Canada, Madrid, Spain. International Space Science Institute, Hallerstrasse 6, CH-3012 Bern, Switzerland. ; Scientific Support Office, European Space Agency, 2201 Noordwijk, Netherlands. ; Department of Physics and Astronomy, Uppsala University, Box 516, 75120 Uppsala, Sweden. Polish Academy of Sciences Space Research Center, Bartycka 18A, PL-00716 Warszawa, Poland. ; Institute for Geophysics and Extraterrestrial Physics, Technische Universitat Braunschweig, Braunschweig 38106, Germany. ; Istituto di Astrofisica e Planetologia Spaziali, Istituto Nazionale di Astrofisica (INAF), Via Fosso del Cavaliere, 100, 0133 Rome, Italy. Universita degli Studi di Napoli "Parthenope," Dipartimento di Scienze e Tecnologie, CDN IC4, 80143 Naples, Italy. ; Department of Astronomy, University of Maryland, College Park, MD 20742-2421, USA. ; European Space Agency (ESA)-European Space Astronomy Center (ESAC), Camino Bajo del Castillo, s/n, 28692 Villanueva de la Canada, Madrid, Spagna. ; Department of Mechanical Engineering, University of Padova, via Venezia 1, 35131 Padova, Italy. ; Laboratoire d'Etudes Spatiales et d'Instrumentation en Astrophysique, Observatoire de Paris, CNRS, Universite Paris 06, Universite Paris-Diderot, 5 place Johannes Janssen, 92195 Meudon, France. ; Laboratoire Atmospheres, Milieux, Observations Spatiales, CNRS/Universite de Versailles Saint-Quentin-en-Yvelines/Institut Pierre-Simon Laplace, 11 boulevard d'Alembert, 78280 Guyancourt, France. ; University of Padova, Centro Interdipartimentale di Studi e Attivita Spaziali (CISAS), via Venezia 15, 35100 Padova, Italy. ; Universita degli Studi di Napoli "Parthenope," Dipartimento di Scienze e Tecnologie, CDN IC4, 80143 Naples, Italy. ; ESA, European Space Research and Technology Centre (ESTEC), Keplerlaan 1, 2201 AZ Noordwijk, Netherlands. ; Selex-ES, Via Albert Einstein, 35, 50013 Campi Bisenzio, Firenze, Italy. ; Osservatorio Astronomico di Padova, INAF, Vicolo dell'Osservatorio 5, 35122 Padova, Italy. ; Consiglio Nazionale delle Ricerche-Istituto di Fotonica e Nanotecnologie-Unita Operativa di Supporto Padova LUXOR, via Trasea 7, 35131 Padova, Italy. ; Department of Physics and Astronomy, Uppsala University, Box 516, 75120 Uppsala, Sweden. ; Universita di Trento, via Mesiano, 77, 38100 Trento, Italy. ; Osservatorio Astronomico di Capodimonte, INAF, Salita Moiariello, 16, 80133 Naples, Italy. ; Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA. ; University of Florida, Gainesville, FL 32611, USA. ; Planetary and Space Sciences, Department of Physical Sciences, The Open University, Milton Keynes MK7 6AA, UK. ; Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany. ; Institute of Planetary Research, Deutsches Zentrum fur Luft- und Raumfahrt (DLR), Rutherfordstrasse 2, 12489 Berlin, Germany. ; Institute for Space Science, National Central University, 300 Chung Da Road, 32054 Chung-Li, Taiwan. ; The University of Kent, School of Physical Sciences, Canterbury, Kent CT2 7NZ, UK. ; Department of Physics, University of Padova, 35131 Padova, Italy. ; Planetary and Space Sciences, Department of Physical Sciences, The Open University, Milton Keynes MK7 6AA, UK. The University of Kent, School of Physical Sciences, Canterbury, Kent CT2 7NZ, UK. Unispacekent, Canterbury CT2 8EF, UK. ; Institut fur Datentechnik und Kommunikationsnetze, 38106 Braunschweig, Germany. ; Departamento de Fisica Aplicada, Universidad de Granada, Facultad de Ciencias, Avenida Severo Ochoa, s/n, 18071 Granada, Spain. ; Department of Information Engineering, Padova University, via Gradenigo 6, 35131 Padova, Italy. ; Laboratoire Atmospheres, Milieux, Observations Spatiales, CNRS/Universite de Versailles Saint-Quentin-en-Yvelines/Institut Pierre-Simon Laplace, 11 boulevard d'Alembert, 78280 Guyancourt, France. Observatoire de Haute Provence OSU Pytheas UMS 2244 CNRS-AMU, 04870 Saint Michel l'Observatoire, France. ; Instituto Nacional de Tecnica Aeroespacial, Carretera de Ajalvir, p.k. 4, 28850 Torrejon de Ardoz, Madrid, Spain. ; Max-Planck-Institut fur Sonnensystemforschung, Justus-von-Liebig-Weg, 3, 37077 Gottingen, Germany. Planetary and Space Sciences, Department of Physical Sciences, The Open University, Milton Keynes MK7 6AA, UK. ; Physikalisches Institut, Sidlerstrasse 5, University of Bern, 3012 Bern, Switzerland. ; Planetary Science Section, Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109, USA. ; International Space Science Institute, Hallerstrasse 6, CH-3012 Bern, Switzerland. Planetary and Space Sciences, Department of Physical Sciences, The Open University, Milton Keynes MK7 6AA, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25613898" target="_blank"〉PubMed〈/a〉