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1. OMEGA/Mars Express: South Pole Region, water vapor daily variability

Author

Yves Langevin, D. V. Titov, Luca Maltagliati, Pierre Drossart, Mathieu Vincendon, Francesca Altieri, R. Melchiorri, François Forget, T. Encrenaz, Jean-Pierre Bibring, T. Fouchet, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Ingénieurs, Techniciens et Administratifs, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Institut d'astrophysique spatiale (IAS), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES)

Subjects
Solar System, 010504 meteorology & atmospheric sciences, Meteorology, Astronomy and Astrophysics, Atmosphere of Mars, Mars Exploration Program, Atmospheric sciences, 01 natural sciences, Regolith, Atmosphere, OMEGA, [SDU]Sciences of the Universe [physics], Satellite, 13. Climate action, Space and Planetary Science, Mars express, Local time, 0103 physical sciences, Environmental science, Martian polar ice caps, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Image spectroscopy, 010303 astronomy & astrophysics, Water vapor, 0105 earth and related environmental sciences
Abstract

Polar regions on Mars are the most suitable places to observe water vapor daily variability because in any observation crossing the Pole we can observe very different local time and because the poles are considered to be the main permanent and seasonal water reservoir of the planet. We report on a daily variability of water vapor in the South Pole Region (SPR), observed by OMEGA/Mars Express during the south spring–summer period ( Ls ∼ 250 ° – 270 ° ) outside the CO 2 ice cap, that has never been observed before by other instruments. We have been able to estimate an increase of few precipitable microns during the day. A possible scenario includes the presence of regolith, or another component that could gather water from the atmosphere, adsorbing the water into the surface during the night time and desorbing it as soon as the Sun reaches sufficient height to heat the ground. This hypothesis is even more plausible considering the presence of observed local enhancements in the morning sections associated with the illumination of the Sun and the total absence in the data for water ice.

Published
2009

2. A study of the Martian water vapor over Hellas using OMEGA and PFS aboard Mars Express

Author

B. Gondet, Yves Langevin, Jean-Pierre Bibring, Pierre Drossart, Luca Maltagliati, D. V. Titov, Vittorio Formisano, Th. Encrenaz, François Forget, R. Melchiorri, T. Fouchet, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Istituto di Fisica dello Spazio Interplanetario (IFSI), and National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR)

Subjects
Physics, Martian, Solar System, Meteorology, Imaging spectrometer, Astronomy and Astrophysics, Mars Exploration Program, Equinox, Astrophysics, Atmospheric sciences, Omega, Space and Planetary Science, Solstice, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Water vapor
Abstract

International audience; We used the OMEGA imaging spectrometer aboard Mars Express to study the evolution of the water vapor abundance over the Hellas basin, as a function of the seasonal cycle. The H2O column density is found to range from very low values (between southern fall and winter) up to more than 15 pr-mum during southern spring and summer. The general behavior is consistent with the expected seasonal cycle of water vapor on Mars, as previously observed by TES and modeled. In particular, the maximum water vapor content is observed around the southern solstice, and is significantly less than its northern couterpart. However, there is a noticeable discrepancy around the northern spring equinox (Ls = 330-60°), where the observed H2O column densities are significantly lower than the values predicted by the GCM. Our data show an abrupt enhancement of the water vapor column density (from 3 to 16 pr-mum) on a timescale of 3 days, for Ls = 251-254°. Such an increase, not predicted by the GCM, was also occasionally observed by TES over Hellas during previous martian years at the same season; however, its origin remains to be understood.

Published
2008

3. Observations of atmospheric water vapor above the Tharsis volcanoes on Mars with the OMEGA/MEx imaging spectrometer

Author

Yves Langevin, Jean-Pierre Bibring, D. V. Titov, Threrese Encrenaz, François Forget, Luca Maltagliati, Maya García-Comas, R. Melchiorri, H. U. Keller, Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Departement de recherche SPAtiale (DESPA), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Ingénieurs, Techniciens et Administratifs, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Institut d'astrophysique spatiale (IAS), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES)

Subjects
geography, geography.geographical_feature_category, Meteorology, Astronomy and Astrophysics, Mars Exploration Program, Atmospheric sciences, Atmosphere, Volcano, Space and Planetary Science, Solar time, Mixing ratio, Environmental science, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Water vapor, Air mass, Tharsis
Abstract

International audience; The OMEGA imaging spectrometer onboard the Mars Express spacecraft is particularly well suited to study in detail specific regions of Mars, thanks to its high spatial resolution and its high signal-to-noise ratio. We investigate the behavior of atmospheric water vapor over the four big volcanoes located on the Tharsis plateau (Olympus, Ascraeus, Pavonis and Arsia Mons) using the 2.6 mum band, which is the strongest and most sensitive H 2O band in the OMEGA spectral range. Our data sample covers the end of MY26 and the whole MY27, with gaps only in the late northern spring and in northern autumn. The most striking result of our retrievals is the increase of water vapor mixing ratio from the valley to the summit of volcanoes. Corresponding column density is often almost constant, despite a factor of ˜5 decrease in air mass from the bottom to the top. This peculiar water enrichment on the volcanoes is present in 75% of the orbits in our sample. The seasonal distribution of such enrichment hints at a seasonal dependence, with a minimum during the northern summer and a maximum around the northern spring equinox. The enrichment possibly also has a diurnal trend, being the orbits with a high degree of enrichment concentrated in the early morning. However, the season and the solar time of the observations, due to the motion of the spacecraft, are correlated, then the two dependences cannot be clearly disentangled. Several orbits exhibit also spatially localized enrichment structures, usually ring- or crescent-shaped. We retrieve also the height of the saturation level over the volcanoes. The results show a strong minimum around the aphelion season, due to the low temperatures, while it raises quickly before and after this period. The enrichment is possibly generated by the local circulation characteristic of the volcano region, which can transport upslope significant quantities of water vapor. The low altitude of the saturation level during the early summer can then hinder the transport of water during this season. The influence of the coupling between atmosphere and surface, due mainly to the action of the regoliths, can also contribute partially to the observed phenomenon.

Published
2008

4. Water vapor mapping on Mars using OMEGA/Mars Express

Author

Jean-Pierre Bibring, Bernard Schmitt, Pierre Drossart, B. Gondet, Yves Langevin, T. Fouchet, E. Lellouch, Nikolay Ignatiev, D. V. Titov, T. Encrenaz, R. Melchiorri, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Planétologie de Grenoble (LPG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Space Research Institute of the Russian Academy of Sciences (IKI), Russian Academy of Sciences [Moscow] (RAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), and Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS)

Subjects
Martian, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010504 meteorology & atmospheric sciences, Imaging spectrometer, Mars, Astronomy and Astrophysics, Equinox, Mars Exploration Program, Atmosphere of Mars, Atmospheric sciences, 01 natural sciences, Omega, Latitude, Mars atmosphere, 13. Climate action, Space and Planetary Science, 0103 physical sciences, Environmental science, Infrared spectroscopy, 010303 astronomy & astrophysics, Water vapor, 0105 earth and related environmental sciences
Abstract

International audience; A systematic mapping of water vapor on Mars has been achieved using the imaging spectrometer OMEGA aboard the Mars Express spacecraft, using the depth of the 2.6 μm (ν1, ν3) band of H2O. We report results obtained during two periods: (1) Ls=330–40° (January–June 2004), before and after the equinox, and (2) Ls=90–125°, which correspond to early northern summer. At low latitude, our results are globally consistent with previous measurements from ground-based and space (MAWD/Viking and TES/MGS) observations. However, at early northern summer and at high northern latitude (70–80 °N), the water vapor abundances, which we retrieved, appear to be weaker than MAWD and TES results. At the time of water sublimation during early northern summer, there is a maximum of water vapor content at latitudes 75–80°N and longitudes 210–24°E. This region is not far from the area where OMEGA identified a high abundance of calcium-rich sulfates, most likely gypsum. Our data provide the first high-resolution map of the martian water vapor content above the northern polar cap.

Published
2007

5. Phyllosilicates on Mars and implications for early martian climate

Author

F, Poulet, J-P, Bibring, J F, Mustard, A, Gendrin, N, Mangold, Y, Langevin, R E, Arvidson, B, Gondet, C, Gomez, M, Berthé, S, Erard, O, Forni, N, Manaud, G, Poulleau, A, Soufflot, M, Combes, P, Drossart, T, Encrenaz, T, Fouchet, R, Melchiorri, G, Bellucci, F, Altieri, V, Formisano, S, Fonti, F, Capaccioni, P, Cerroni, A, Coradini, O, Korablev, V, Kottsov, N, Ignatiev, D, Titov, L, Zasova, P, Pinet, B, Schmitt, C, Sotin, E, Hauber, H, Hoffmann, R, Jaumann, U, Keller, F, Forget, Interactions et dynamique des environnements de surface (IDES), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and CRINON, Evelyne

Subjects
Extraterrestrial Environment, 010504 meteorology & atmospheric sciences, Climate, Iron, Mars, 01 natural sciences, Astrobiology, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, 0103 physical sciences, Magnesium, Composition of Mars, Spacecraft, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Martian, Mineral hydration, Multidisciplinary, Mineral, Sulfates, Noachian, Water, Mars Exploration Program, Hydrogen-Ion Concentration, Space Flight, CRISM, 13. Climate action, Clay, Hesperian, Aluminum Silicates, [SDU.STU.PL] Sciences of the Universe [physics]/Earth Sciences/Planetology, Geology
Abstract

The recent identification of large deposits of sulphates by remote sensing and in situ observations has been considered evidence of the past presence of liquid water on Mars. Here we report the unambiguous detection of diverse phyllosilicates, a family of aqueous alteration products, on the basis of observations by the OMEGA imaging spectrometer on board the Mars Express spacecraft. These minerals are mainly associated with Noachian outcrops, which is consistent with an early active hydrological system, sustaining the long-term contact of igneous minerals with liquid water. We infer that the two main families of hydrated alteration products detected-phyllosilicates and sulphates--result from different formation processes. These occurred during two distinct climatic episodes: an early Noachian Mars, resulting in the formation of hydrated silicates, followed by a more acidic environment, in which sulphates formed.

Published
2005

6. A mapping of martian water sublimation during early northern summer using OMEGA/Mars Express

Author

T. Encrenaz, Yves Langevin, R. Melchiorri, Nikolay Ignatiev, François Forget, B. Gondet, E. Lellouch, J. P. Bibring, D. V. Titov, T. Fouchet, Pierre Drossart, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Ingénieurs, Techniciens et Administratifs, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Max Planck Institute (MPI), Space Research Institute of the Russian Academy of Sciences (IKI), Russian Academy of Sciences [Moscow] (RAS), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)

Subjects
Martian, Physics, Northern Hemisphere, Astronomy and Astrophysics, Astrophysics, Atmospheric sciences, Omega, Astrobiology, Latitude, [SDU]Sciences of the Universe [physics], Space and Planetary Science, Martian surface, Mixing ratio, Sublimation (phase transition), [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Water vapor
Abstract

International audience; The OMEGA imaging spectrometer aboard Mars Express has been used to map the water vapor abundance over the martian surface, from the analysis of the 2.6 mum band of H2O. As a preliminary result of this study, we present water vapor maps in the northern hemisphere at the time of the northern polar cap sublimation (Ls = 94-112 deg). The maps show a mean H2O mixing ratio of about 2-3× 10-4 at a latitude of 40N, and in the range of 5 × 10-4-10-3 at 60N-80N latitudes. The corresponding mean H2O column densities are about 25 pr-mum at 40N and between 40 and 60 pr-mum at 60N-80N, with uncertainties of about 30 percent. Our results are in agreement with previous results by MAWD/Viking and TES/MGS for latitudes up to 60N, but seem to indicate lower values at high latitude. However they are still globally consistent in view of our error bars.

Published
2005

7. VISPO project: visible image-spectrometer for planetary observations

Author

Angioletta Coradini, Fabrizio Capaccioni, Gianrico Filacchione, R. Melchiorri, M. De Petris, and Giuseppe Piccioni

Subjects
extrinction, planets and satellites : general, Cosmology, law.invention, Telescope, Far infrared, law, spectrographs, Calibration, virtis, Instrumentation (computer programming), Instrumentation, Remote sensing, Physics, Spectrometer, calibration, cosmology : observations, cosmology: observations, dust, instrumentation, mito, planets and satellites: general, space vehicles, telescopes, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Ranging, Space and Planetary Science, Satellite
Abstract

Satellite instrumentations designed for planetary studies are often open to other interesting applications from ground: not only one can efficiently carry out detailed calibrations before space data become available, but also the prototypes of the satellite instruments can be successfully employed in different fields ranging from astrophysics to cosmology. Both possibilities are opened by coupling these instruments with ground based telescopes having short focal ratios, like those designed for far infrared studies. These possibilities are particularly amazing in view of the long delay usually present between the launch and the collection of the first scientific data (months in case of Mars Express, years in case of Rosetta). We propose in this article to employ immediately this technology, by coupling the developing model of the Image-Spectrometer VIRTIS-M with the ground telescope MITO. This project will allow us to perform a better calibration of the space qualified instrument and observational campaigns, including some important cosmological investigations.

Published
2004

8. VIRTIS-M flight lamps

Author

R. Melchiorri, Alessandro Mazzoni, and Giuseppe Piccioni

Subjects
Physics, business.product_category, visible spectrometer, Spectrometer, business.industry, infrared sources, Effective temperature, calibration, infrare spectrometer, Optics, aerospace instrument, Rocket, Asteroid, Calibration, Light emission, business, Optical filter, Instrumentation, Diode
Abstract

VIRTIS-M is a visible-infrared (VIS-IR) image spectrometer designed for the Rosetta mission; it intends to provide detailed informations on the physical, chemical, and mineralogical nature of comets and asteroids. The in-flight performances of VIRTIS-M are expected to be influenced by various disturbances, like the initial strong vibrations of the rocket, the long duration of the experiment (from 2003 to 2010), as well as other possible environmental changes; therefore, an in-flight recalibration procedure is mandatory. Quite often in such kinds of missions, a light emission diode (LED) is employed to calibrate the on-board spectrometers by taking advantage of the relative small dimensions, stability, and hardness of these sources. VIRTIS-M is the first image spectrometer that will use a new generation of lamps for internal calibrations. These new lamps are characterized by a wide spectral range with a blackbody-like emission with an effective temperature of about (2400–2600 K), thereby covering the whole VIRTIS-M's spectral range (0.2–5 µm); i.e., they offer the possibility of a wider spectral calibration in comparison with the quasimonochromatic LED emission. A precise spectral calibration is achieved by adding special filters for visible and infrared ranges in front of the window source, containing many narrow absorption lines. In the present article, we describe the calibration and tests of some flight prototypes of these lamps (VIS and IR), realized by the Officine Galileo and calibrated by the Consiglio Nazionale delle Ricerche–Istituto di Astrofisica Spaziale e Fisica Cosmica.

Published
2003

9. Annual survey of water vapor behavior from the OMEGA mapping spectrometer onboard Mars Express

Author

Jean-Pierre Bibring, H. U. Keller, Luca Maltagliati, Dmitrij V. Titov, François Forget, Thérèse Encrenaz, R. Melchiorri, Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Observatoire de Paris - Site de Meudon (OBSPM), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), IAS / CNRS / Universite Paris XI, Max-Planck-Institut für Sonnensystemforschung (MPS), Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)

Subjects
010504 meteorology & atmospheric sciences, Infrared observations, Atmospheric circulation, Northern Hemisphere, Mars, Astronomy and Astrophysics, Mars Exploration Program, Atmosphere of Mars, Atmospheric sciences, 01 natural sciences, Latitude, Atmosphere, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], 0103 physical sciences, atmosphere, atmospheres, Environmental science, Abundances, Water cycle, 010303 astronomy & astrophysics, climate, Water vapor, 0105 earth and related environmental sciences
Abstract

We present here the annual behavior of atmospheric water vapor on Mars, as observed by the OMEGA spectrometer on board Mars Express during its first martian year. We consider all the different features of the cycle of water vapor: temporal evolution, both at a seasonal and at a diurnal scale; longitudinal distribution; and the vertical profile, through the variations in the saturation height. We put our results into the context of the current knowledge on the water cycle through a systematic comparison with the already published datasets. The seasonal behavior is in very good agreement with past and simultaneous retrievals both qualitatively and quantitatively, within the uncertainties. The average water vapor abundance during the year is ∼10 pr. μm, with an imbalance between northern and southern hemisphere, in favor of the first. The maximum of activity, up to 60 pr. μm, occurs at high northern latitudes during local summer and shows the dominance of the northern polar cap within the driving processes of the water cycle. A corresponding maximum at southern polar latitudes during the local summer is present, but less structured and intense. It reaches ∼25 pr. μm at its peak. Global circulation has some influence in shaping the water cycle, but it is less prominent than the results from previous instruments suggest. No significant correlation between water vapor column density and local hour is detected. We can constrain the amount of water vapor exchanged between the surface and the atmosphere to few pr. μm. This is consistent with recent results by OMEGA and PFS-LW. The action of the regolith layer on the global water cycle seems to be minor, but it cannot be precisely constrained. The distribution of water vapor on the planet, after removing the topography, shows the already known two-maxima system, over Tharsis and Arabia Terra. However, the Arabia Terra increase is quite fragmented compared with previous observations. A deep zone of minimum separates the two regions. The saturation height of water vapor is mainly governed by the variations of insolation during the year. It is confined within 5–15 km from the surface at aphelion, while in the perihelion season it stretches up to 55 km of altitude.

Published
2011

10. A study of the properties of a local dust storm with Mars Express OMEGA and PFS data

Author

Olivier Forni, Marco Giuranna, Vittorio Formisano, Anni Määttänen, Brigitte Gondet, François Forget, Thierry Fouchet, R. Melchiorri, Hannu Savijärvi, Yves Langevin, Jean-Pierre Bibring, Department of Physics [Helsinki], Falculty of Science [Helsinki], Helsingin yliopisto = Helsingfors universitet = University of Helsinki-Helsingin yliopisto = Helsingfors universitet = University of Helsinki, Finnish Meteorological Institute (FMI), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Centre d'étude spatiale des rayonnements (CESR), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), University of Helsinki-University of Helsinki, Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Consiglio Nazionale delle Ricerche (CNR)

Subjects
Atmospheres, 010504 meteorology & atmospheric sciences, Mars, Atmospheric model, Astrophysics::Cosmology and Extragalactic Astrophysics, Atmospheric sciences, 01 natural sciences, Atmosphere, Atmospheric radiative transfer codes, Dust storm, 0103 physical sciences, Radiative transfer, Astrophysics::Solar and Stellar Astrophysics, structure, Terrestrial planets, 010303 astronomy & astrophysics, Physics::Atmospheric and Oceanic Physics, Astrophysics::Galaxy Astrophysics, Spectroscopy, 0105 earth and related environmental sciences, Remote sensing, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astronomy and Astrophysics, Storm, Mars Exploration Program, Albedo, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], atmosphere, Environmental science, Astrophysics::Earth and Planetary Astrophysics
Abstract

International audience; We present observations of a local dust storm performed by the OMEGA and PFS instruments aboard Mars Express. OMEGA observations are used to retrieve the dust single-scattering albedo in the spectral range 0.4–4.0 μm. The single-scattering albedo shows fairly constant values between 0.6–2.6 μm, and a sharp decrease at wavelengths shorter than 0.6 μm, in agreement with previous studies. It presents a small absorption feature due to ferric oxide at 0.9 μm, and a strong absorption feature due to hydrated minerals between 2.7–3.6 μm. We use a statistical method, the Independent Component Analysis, to determine that the dust spectral signature is decoupled from the surface albedo, proving that the retrieval of the single-scattering albedo is reliable, and we map the dust optical thickness with a conventional radiative transfer model. The effect of the dust storm on the atmospheric thermal structure is measured using PFS observations. We also simulate the thermal impact of the dust storm using a one-dimensional atmospheric model. A comparison of the retrieved and modeled temperature structures suggests that the dust in the storm should be confined to the 1–2 lowest scale heights of the atmosphere. However, the observed OMEGA reflectance in the CO absorption bands does not support this suggestion.

Published
2009

11. Remote sensing of surface pressure on Mars with the Mars Express/OMEGA spectrometer: 2. Meteorological maps

Author

Yves Langevin, Sandrine Vinatier, Aline Gendrin, Brigitte Gondet, Aymeric Spiga, François Forget, Pierre Drossart, R. Melchiorri, Bastien Dolla, and Jean-Pierre Bibring

Subjects
Martian, Atmospheric Science, Ice cloud, Ecology, Mesoscale meteorology, Paleontology, Soil Science, Forestry, Atmosphere of Mars, Mars Exploration Program, Aquatic Science, Oceanography, Surface pressure, Geophysics, Space and Planetary Science, Geochemistry and Petrology, Martian surface, Earth and Planetary Sciences (miscellaneous), Astrophysics::Earth and Planetary Astrophysics, Physics::Atmospheric and Oceanic Physics, Pressure gradient, Geology, Earth-Surface Processes, Water Science and Technology, Remote sensing
Abstract

[1] Surface pressure measurements help to achieve a better understanding of the main dynamical phenomena occurring in the atmosphere of a planet. The use of the Mars Express OMEGA visible and near-IR imaging spectrometer allows us to tentatively perform an unprecedented remote sensing measurement of Martian surface pressure. OMEGA reflectances in the CO2 absorption band at 2 μm are used to retrieve a hydrostatic estimation of surface pressure (see companion paper by Forget et al. (2007)) with a precision sufficient to draw maps of this field and thus analyze meteorological events in the Martian atmosphere. Prior to any meteorological analysis, OMEGA observations have to pass quality controls on insolation and albedo conditions, atmosphere dust opacity, and occurrence of water ice clouds and frosts. For the selected observations, registration shifts with the MOLA reference are corrected. “Sea-level” surface pressure reduction is then carried out in order to remove the topographical component of the surface pressure field. Three main phenomena are observed in the resulting OMEGA surface pressure maps: horizontal pressure gradients, atmospheric oscillations, and pressure perturbations in the vicinity of topographical obstacles. The observed pressure oscillations are identified as possible signatures of phenomena such as inertia-gravity waves or convective rolls. The pressure perturbations detected around the Martian hills and craters may be the signatures of complex interactions between an incoming flow and topographical obstacles. Highly idealized mesoscale simulations using the WRF model enable a preliminary study of these complex interactions, but more realistic mesoscale simulations are necessary. The maps provide valuable insights for future synoptic and mesoscale modeling, which will in turn help in the interpretation of observations.

Published
2007

12. Remote sensing of surface pressure on Mars with the Mars Express/OMEGA spectrometer: 1. Retrieval method

Author

R. Melchiorri, Yves Langevin, Sandrine Vinatier, Aline Gendrin, Brigitte Gondet, Aymeric Spiga, Jean-Pierre Bibring, Pierre Drossart, François Forget, and Bastien Dolla

Subjects
Atmospheric Science, Imaging spectrometer, Soil Science, Aquatic Science, Oceanography, Surface pressure, law.invention, Atmosphere, Optics, Atmospheric radiative transfer codes, Geochemistry and Petrology, law, Earth and Planetary Sciences (miscellaneous), Pressure gradient, Earth-Surface Processes, Water Science and Technology, Remote sensing, Ecology, Spectrometer, business.industry, Paleontology, Forestry, Mars Exploration Program, Geophysics, Pressure measurement, Space and Planetary Science, Environmental science, business
Abstract

[1] Observing and analyzing the variations of pressure on the surface of a planet is essential to understand the dynamics of its atmosphere. On Mars the absorption by atmospheric CO2 of the solar light reflected on the surface allows us to measure the surface pressure by remote sensing. We use the imaging spectrometer OMEGA aboard Mars Express, which provides an excellent signal to noise ratio and the ability to produce maps of surface pressure with a resolution ranging from 400 m to a few kilometers. Surface pressure is measured by fitting spectra of the CO2 absorption band centered at 2 μm. To process the hundreds of thousands of pixels present in each OMEGA image, we have developed a fast and accurate algorithm based on a line-by-line radiative transfer model which includes scattering and absorption by dust aerosols. In each pixel the temperature profile, the dust opacity, and the surface spectrum are carefully determined from the OMEGA data set or from other sources to maximize the accuracy of the retrieval. We estimate the 1-σ relative error to be around 7 Pa in bright regions and about 10 Pa in darker regions, with a possible systematic bias on the absolute pressure lower than 30 Pa (4%). The method is first tested by comparing an OMEGA pressure retrieval obtained over the Viking Lander 1 (VL1) landing site with in situ measurements recorded 30 years ago by the VL1 barometer. The retrievals are further validated using a surface pressure predictor which combines the VL1 pressure records with the MOLA topography and meteorological pressure gradients simulated with a General Circulation Model. A good agreement is obtained. In particular, OMEGA is able to monitor the seasonal variations of the surface pressure in Isidis Planitia. Such a tool can be applied to detect meteorological phenomena, as described by Spiga et al. (2007).

Published
2007

13. Seasonal variations of the martian CO over Hellas as observed by OMEGA/Mars Express

Author

Bruno Bézard, François Forget, Yves Langevin, Jean-Pierre Bibring, Th. Encrenaz, R. Melchiorri, B. Gondet, Pierre Drossart, T. Fouchet, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Ingénieurs, Techniciens et Administratifs, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)

Subjects
Martian, Physics, Solar System, Meteorology, Imaging spectrometer, Astronomy and Astrophysics, Astrophysics, Atmospheric sciences, Surface pressure, Omega, Latitude, Space and Planetary Science, Planet, Spatial variability, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience; The OMEGA imaging spectrometer aboard Mars Express has been used to study the evolution of the CO abundance over the Hellas basin, as a function of the seasonal cycle. In spite of significant uncertainties, due to the low intensity of the (2-0) CO band at 2.3 mum, these data allow to search for spatial variations over Hellas, where the surface pressure and the CO band depth are maximum. The OMEGA data suggest an enhancement over Hellas at Ls = 130-150 deg (end of southern winter), by a factor of about 2 with regard to Ls = 330-350 deg (end of northern summer). This behavior is to be compared with the evolution of argon, another non-condensible species which also shows strong variations with Ls at southern latitudes (Sprague et al. 2004). This result appears also consistent with the GCM predictions which indicate an enrichment by a factor of about 2 of non-condensible species over Hellas during southern winter (Forget et al. 2006).

Published
2006

14. Perennial water ice identified in the south polar cap of Mars

Author

Thomas C. Duxbury, U. Keller, Yves Langevin, A. Soufflot, François Poulet, Aline Gendrin, Stéphane Erard, V. I. Moroz, Nicolas Mangold, Vittorio Formisano, François Forget, Dmitri Titov, Bernard Schmitt, G. Bonello, G. Poulleau, Pierre Drossart, T. Fouchet, V. Kottsov, M. Combes, Jean-Pierre Bibring, Olivier Forni, John F. Mustard, Francesca Altieri, Patrick Pinet, Christophe Sotin, Angioletta Coradini, N. Manaud, B. Gondet, Sergio Fonti, Ernst Hauber, L. V. Zasova, Priscilla Cerroni, Michel Berthé, T. Encrenaz, R. Melchiorri, Raymond E. Arvidson, Ralf Jaumann, G. Belluci, Nikolay Ignatiev, Harald Hoffmann, Fabrizio Capaccioni, Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Institute of Space Research, Russian Academy of Science (IKI/RAN), ORSAYTERRE, Université Paris-Sud - Paris 11 (UP11), Laboratoire de Planétologie de Grenoble (LPG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Aeronomie (MPAe), Department of Earth and Planetary Sciences, Washington University, Department of Geological Science, Brown University, Jet Propulsion Laboratory, California Institute of Technology (JPL), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)

Subjects
Martian, Carbon dioxide clathrate, Multidisciplinary, Water on Mars, Extraterrestrial Environment, Geography, Ice, chemistry.chemical_element, Mars, Water, Mars Exploration Program, Carbon Dioxide, Astrobiology, chemistry.chemical_compound, chemistry, Perennial water, Carbon dioxide, Exobiology, Martian polar ice caps, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Carbon, Geology
Abstract

International audience; The inventory of water and carbon dioxide reservoirs on Mars are important clues for understanding the geological, climatic and potentially exobiological evolution of the planet. From the early mapping observation of the permanent ice caps on the martian poles, the northern cap was believed to be mainly composed of water ice, whereas the southern cap was thought to be constituted of carbon dioxide ice. However, recent missions (NASA missions Mars Global Surveyor and Odyssey) have revealed surface structures, altimetry profiles, underlying buried hydrogen, and temperatures of the south polar regions that are thermodynamically consistent with a mixture of surface water ice and carbon dioxide. Here we present the first direct identification and mapping of both carbon dioxide and water ice in the martian high southern latitudes, at a resolution of 2km, during the local summer, when the extent of the polar ice is at its minimum. We observe that this south polar cap contains perennial water ice in extended areas: as a small admixture to carbon dioxide in the bright regions; associated with dust, without carbon dioxide, at the edges of this bright cap; and, unexpectedly, in large areas tens of kilometres away from the bright cap.

Published
2004

15. Hygroscopic salts and the potential for life on Mars.

Author

Davila AF, Duport LG, Melchiorri R, Jänchen J, Valea S, de Los Rios A, Fairén AG, Möhlmann D, McKay CP, Ascaso C, and Wierzchos J

Subjects
Absorption, Climate, Exobiology, Extraterrestrial Environment, Humidity, Partial Pressure, Steam, Hygroscopic Agents chemistry, Mars, Salts chemistry, Water chemistry
Abstract

Hygroscopic salts have been detected in soils in the northern latitudes of Mars, and widespread chloride-bearing evaporitic deposits have been detected in the southern highlands. The deliquescence of hygroscopic minerals such as chloride salts could provide a local and transient source of liquid water that would be available for microorganisms on the surface. This is known to occur in the Atacama Desert, where massive halite evaporites have become a habitat for photosynthetic and heterotrophic microorganisms that take advantage of the deliquescence of the salt at certain relative humidity (RH) levels. We modeled the climate conditions (RH and temperature) in a region on Mars with chloride-bearing evaporites, and modeled the evolution of the water activity (a(w)) of the deliquescence solutions of three possible chloride salts (sodium chloride, calcium chloride, and magnesium chloride) as a function of temperature. We also studied the water absorption properties of the same salts as a function of RH. Our climate model results show that the RH in the region with chloride-bearing deposits on Mars often reaches the deliquescence points of all three salts, and the temperature reaches levels above their eutectic points seasonally, in the course of a martian year. The a(w) of the deliquescence solutions increases with decreasing temperature due mainly to the precipitation of unstable phases, which removes ions from the solution. The deliquescence of sodium chloride results in transient solutions with a(w) compatible with growth of terrestrial microorganisms down to 252 K, whereas for calcium chloride and magnesium chloride it results in solutions with a(w) below the known limits for growth at all temperatures. However, taking the limits of a(w) used to define special regions on Mars, the deliquescence of calcium chloride deposits would allow for the propagation of terrestrial microorganisms at temperatures between 265 and 253 K, and for metabolic activity (no growth) at temperatures between 253 and 233 K.

Published
2010
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16. A dynamic upper atmosphere of Venus as revealed by VIRTIS on Venus Express.

Author

Drossart P, Piccioni G, Gérard JC, Lopez-Valverde MA, Sanchez-Lavega A, Zasova L, Hueso R, Taylor FW, Bézard B, Adriani A, Angrilli F, Arnold G, Baines KH, Bellucci G, Benkhoff J, Bibring JP, Blanco A, Blecka MI, Carlson RW, Coradini A, Di Lellis A, Encrenaz T, Erard S, Fonti S, Formisano V, Fouchet T, Garcia R, Haus R, Helbert J, Ignatiev NI, Irwin P, Langevin Y, Lebonnois S, Luz D, Marinangeli L, Orofino V, Rodin AV, Roos-Serote MC, Saggin B, Stam DM, Titov D, Visconti G, Zambelli M, Tsang C, Ammannito E, Barbis A, Berlin R, Bettanini C, Boccaccini A, Bonnello G, Bouyé M, Capaccioni F, Cardesin A, Carraro F, Cherubini G, Cosi M, Dami M, De Nino M, Del Vento D, Di Giampietro M, Donati A, Dupuis O, Espinasse S, Fabbri A, Fave A, Veltroni IF, Filacchione G, Garceran K, Ghomchi Y, Giustizi M, Gondet B, Hello Y, Henry F, Hofer S, Huntzinger G, Kachlicki J, Knoll R, Kouach D, Mazzoni A, Melchiorri R, Mondello G, Monti F, Neumann C, Nuccilli F, Parisot J, Pasqui C, Perferi S, Peter G, Piacentino A, Pompei C, Réess JM, Rivet JP, Romano A, Russ N, Santoni M, Scarpelli A, Sémery A, Soufflot A, Stefanovitch D, Suetta E, Tarchi F, Tonetti N, Tosi F, and Ulmer B

Abstract

The upper atmosphere of a planet is a transition region in which energy is transferred between the deeper atmosphere and outer space. Molecular emissions from the upper atmosphere (90-120 km altitude) of Venus can be used to investigate the energetics and to trace the circulation of this hitherto little-studied region. Previous spacecraft and ground-based observations of infrared emission from CO2, O2 and NO have established that photochemical and dynamic activity controls the structure of the upper atmosphere of Venus. These data, however, have left unresolved the precise altitude of the emission owing to a lack of data and of an adequate observing geometry. Here we report measurements of day-side CO2 non-local thermodynamic equilibrium emission at 4.3 microm, extending from 90 to 120 km altitude, and of night-side O2 emission extending from 95 to 100 km. The CO2 emission peak occurs at approximately 115 km and varies with solar zenith angle over a range of approximately 10 km. This confirms previous modelling, and permits the beginning of a systematic study of the variability of the emission. The O2 peak emission happens at 96 km +/- 1 km, which is consistent with three-body recombination of oxygen atoms transported from the day side by a global thermospheric sub-solar to anti-solar circulation, as previously predicted.

Published
2007
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17. South-polar features on Venus similar to those near the north pole.

Author

Piccioni G, Drossart P, Sanchez-Lavega A, Hueso R, Taylor FW, Wilson CF, Grassi D, Zasova L, Moriconi M, Adriani A, Lebonnois S, Coradini A, Bézard B, Angrilli F, Arnold G, Baines KH, Bellucci G, Benkhoff J, Bibring JP, Blanco A, Blecka MI, Carlson RW, Di Lellis A, Encrenaz T, Erard S, Fonti S, Formisano V, Fouchet T, Garcia R, Haus R, Helbert J, Ignatiev NI, Irwin PG, Langevin Y, Lopez-Valverde MA, Luz D, Marinangeli L, Orofino V, Rodin AV, Roos-Serote MC, Saggin B, Stam DM, Titov D, Visconti G, Zambelli M, Ammannito E, Barbis A, Berlin R, Bettanini C, Boccaccini A, Bonnello G, Bouye M, Capaccioni F, Moinelo AC, Carraro F, Cherubini G, Cosi M, Dami M, De Nino M, Del Vento D, Di Giampietro M, Donati A, Dupuis O, Espinasse S, Fabbri A, Fave A, Veltroni IF, Filacchione G, Garceran K, Ghomchi Y, Giustini M, Gondet B, Hello Y, Henry F, Hofer S, Huntzinger G, Kachlicki J, Knoll R, Driss K, Mazzoni A, Melchiorri R, Mondello G, Monti F, Neumann C, Nuccilli F, Parisot J, Pasqui C, Perferi S, Peter G, Piacentino A, Pompei C, Reess JM, Rivet JP, Romano A, Russ N, Santoni M, Scarpelli A, Semery A, Soufflot A, Stefanovitch D, Suetta E, Tarchi F, Tonetti N, Tosi F, and Ulmer B

Abstract

Venus has no seasons, slow rotation and a very massive atmosphere, which is mainly carbon dioxide with clouds primarily of sulphuric acid droplets. Infrared observations by previous missions to Venus revealed a bright 'dipole' feature surrounded by a cold 'collar' at its north pole. The polar dipole is a 'double-eye' feature at the centre of a vast vortex that rotates around the pole, and is possibly associated with rapid downwelling. The polar cold collar is a wide, shallow river of cold air that circulates around the polar vortex. One outstanding question has been whether the global circulation was symmetric, such that a dipole feature existed at the south pole. Here we report observations of Venus' south-polar region, where we have seen clouds with morphology much like those around the north pole, but rotating somewhat faster than the northern dipole. The vortex may extend down to the lower cloud layers that lie at about 50 km height and perhaps deeper. The spectroscopic properties of the clouds around the south pole are compatible with a sulphuric acid composition.

Published
2007
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18. Phyllosilicates on Mars and implications for early martian climate.

Author

Poulet F, Bibring JP, Mustard JF, Gendrin A, Mangold N, Langevin Y, Arvidson RE, Gondet B, Gomez C, Berthé M, Erard S, Forni O, Manaud N, Poulleau G, Soufflot A, Combes M, Drossart P, Encrenaz T, Fouchet T, Melchiorri R, Bellucci G, Altieri F, Formisano V, Fonti S, Capaccioni F, Cerroni P, Coradini A, Korablev O, Kottsov V, Ignatiev N, Titov D, Zasova L, Pinet P, Schmitt B, Sotin C, Hauber E, Hoffmann H, Jaumann R, Keller U, and Forget F

Subjects
Clay, Hydrogen-Ion Concentration, Iron analysis, Magnesium analysis, Space Flight, Spacecraft, Sulfates analysis, Sulfates chemistry, Water analysis, Water chemistry, Aluminum Silicates analysis, Aluminum Silicates chemistry, Climate, Extraterrestrial Environment chemistry, Mars
Abstract

The recent identification of large deposits of sulphates by remote sensing and in situ observations has been considered evidence of the past presence of liquid water on Mars. Here we report the unambiguous detection of diverse phyllosilicates, a family of aqueous alteration products, on the basis of observations by the OMEGA imaging spectrometer on board the Mars Express spacecraft. These minerals are mainly associated with Noachian outcrops, which is consistent with an early active hydrological system, sustaining the long-term contact of igneous minerals with liquid water. We infer that the two main families of hydrated alteration products detected-phyllosilicates and sulphates--result from different formation processes. These occurred during two distinct climatic episodes: an early Noachian Mars, resulting in the formation of hydrated silicates, followed by a more acidic environment, in which sulphates formed.

Published
2005
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