Examinando por Autor "Langlais, B."

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Acceso Abierto
Geodesy, Geophysics and Fundamental Physics Investigations of the BepiColombo Mission
(Springer Link, 2021-02-26) Genova, A.; Hussmann, H.; Van Hoolst, T.; Heyner, D.; Less, L.; Santoli, F.; Thomas, N.; Cappuccio, P.; Di Stefano, I.; Kolhey, P.; Langlais, B.; Mieth, J. Z. D.; Oliveira, A. S.; Stark, A.; Steinbrügge, G.; Tosi, N.; Wicht, J.; Benkhoff, J.; Agenzia Spaziale Italiana (ASI); Bundesministerium für Wirtschaft und Energie (BMWi); Deutsches Zentrum für Luft- und Raumfahrt (DLR); Genova, A. [0000-0001-5584-492X]; Hussmann, H. [0000-0002-3816-0232]; Van Hoolst, T. [0000-0002-9820-8584]; Heyner, D. [0000-0001-7894-8246]; Iess, L. [0000-0002-6230-5825]; Santoli, F. [0000-0003-2493-0109]; Thomas, N. [0000-0002-0146-0071]; Cappuccio, P. [0000-0002-8758-6627]; Di Stefano, I. [0000-0003-1491-6848]; Langlais, B. [0000-0001-5207-304X]; Oliveira, J. S. [0000-0002-4587-2895]; Stark, A. [0000-0001-9110-1138]; Steinbrügge, G. [0000-0002-1050-7759]; Tosi, N. [0000-0002-4912-2848]; Wicht, J. [0000-0002-2440-5091]; Benkhoff, J. [0000-0002-4307-9703]
In preparation for the ESA/JAXA BepiColombo mission to Mercury, thematic working groups had been established for coordinating the activities within the BepiColombo Science Working Team in specific fields. Here we describe the scientific goals of the Geodesy and Geophysics Working Group (GGWG) that aims at addressing fundamental questions regarding Mercury’s internal structure and evolution. This multidisciplinary investigation will also test the gravity laws by using the planet Mercury as a proof mass. The instruments on the Mercury Planetary Orbiter (MPO), which are devoted to accomplishing the GGWG science objectives, include the BepiColombo Laser Altimeter (BELA), the Mercury orbiter radio science experiment (MORE), and the MPO magnetometer (MPO-MAG). The onboard Italian spring accelerometer (ISA) will greatly aid the orbit reconstruction needed by the gravity investigation and laser altimetry. We report the current knowledge on the geophysics, geodesy, and evolution of Mercury after the successful NASA mission MESSENGER and set the prospects for the BepiColombo science investigations based on the latest findings on Mercury’s interior. The MPO spacecraft of the BepiColombo mission will provide extremely accurate measurements of Mercury’s topography, gravity, and magnetic field, extending and improving MESSENGER data coverage, in particular in the southern hemisphere. Furthermore, the dual-spacecraft configuration of the BepiColombo mission with the Mio spacecraft at higher altitudes than the MPO spacecraft will be fundamental for decoupling the internal and external contributions of Mercury’s magnetic field. Thanks to the synergy between the geophysical instrument suite and to the complementary instruments dedicated to the investigations on Mercury’s surface, composition, and environment, the BepiColombo mission is poised to advance our understanding of the interior and evolution of the innermost planet of the solar system.
Acceso Abierto
The formation of a giant collapse caprock sinkhole on the Barda Negra plateau basalts (Argentina): Magnetic, mineralogical and morphostructural evidences
(Elsevier BV, 2020-10-15) Díaz Michelena, M.; Kilian, R.; Baeza, O.; Ríos, F.; Ángel Rivero, M.; Mesa, J. L.; Arlensiú Ordoñez, A.; Langlais, B.; Rocca, M. C. L.; Acevedo, R. D.; González LLorente, Víctor; Agencia Estatal de Investigación (AEI); European Research Council (ERC)
The 1.5-km-wide, 40-m-deep, crater-like structure in the 10 Ma old Barda Negra basaltic plateau in Central Argentina was discovered in the early 2000s. Based on remote sensing surveys and on its morphological characteristics, similar to those of the Barringer crater in Arizona, the structure is described to be originated by an impact. In this study we ran several field work campaigns and collected and analysed samples, in order to find more evidences to endorse or reject this hypothesis. We observe a circular depression not generally surrounded by raised rims, in contrast to craters produced either by a meteorite impact or phreatomagmatic eruption (maars). Mineralogical investigations of rocks and sediments do not show high pressure and temperature minerals, such as coesite or stishovite, or any remnants of an impactite or impact melt/glass. Likewise, no textural evidences for impact-related fracturing or stress are observed. A detailed geomorphological mapping indicates a successive crater development which invokes local stepwise subsidence. Magnetic mapping performed with the EU-funded NEWTON multisensor novel instrument shows a ~2000 nT field anomaly associated to the edges of the crater, and susceptibility measurements cast an important contrast between the basaltic rims and plateau, and the crater interior. Therefore, we propose a sinkhole origin for the crater, with a former collapse of the plateau basalts and a latter infill with sedimentary material. This hypothesis is supported by the fact that the 40 to 85 m thick and 14 to 15 Ma old carbonate-bearing Collón Curá Formation, underneath the 100 to 150 m thick basaltic plateau lava sheet, represents ideal rocks for dissolution and karst formation; remote sensing data show other nearby sinkholes (20 km westward), with extensions of 3 × 6 km and 100 m depth, which are emplaced within a cogenetic neighboring basaltic plateau with a similar underlying lithology; and the consistence of the magnetic model computed with this scheme and on measured rock remanence and susceptibilities of the structure and surroundings. These giant collapse sinkholes, up to 6 km in diameter, within caprocks of very thick plateau basalts, represent unique examples for planetary surface shaping processes which also occur on Mars and comets in areas with basalts or rigid caprocks.