C. Engrand
A5011178605- Astro and Planetary Science
- Planetary Science and Exploration
- Isotope Analysis in Ecology
- Astrophysics and Star Formation Studies
- Geology and Paleoclimatology Research
- Mass Spectrometry Techniques and Applications
- Nuclear Physics and Applications
- Stellar, planetary, and galactic studies
- Space Exploration and Technology
- Atmospheric Ozone and Climate
- Polar Research and Ecology
- High-pressure geophysics and materials
- Astronomical and nuclear sciences
- Ion-surface interactions and analysis
- Paleontology and Stratigraphy of Fossils
- Laser-induced spectroscopy and plasma
- Geological and Geochemical Analysis
- Spacecraft and Cryogenic Technologies
- Space Science and Extraterrestrial Life
- Atomic and Molecular Physics
- Nuclear physics research studies
- Methane Hydrates and Related Phenomena
- Cryospheric studies and observations
- Molecular Spectroscopy and Structure
- Spaceflight effects on biology
Laboratoire de Physique des 2 Infinis Irène Joliot-Curie
2020-2024
Institut National de Physique Nucléaire et de Physique des Particules
2014-2024
Université Paris-Saclay
2015-2024
Centre National de la Recherche Scientifique
2015-2024
Imperial College London
2024
Royal Holloway University of London
2024
Johnson Space Center
2024
Campus France
2011-2021
Mental Health Consumer Survivor Network
2012-2021
Université Paris-Sud
2009-2019
Cometary ices are rich in CO2, CO and organic volatile compounds, but the carbon content of cometary dust was only measured for Oort Cloud comet 1P/Halley, during its flyby 1986. The COmetary Secondary Ion Mass Analyzer (COSIMA)/Rosetta mass spectrometer analysed particles with sizes ranging from 50 to 1000 μm, collected over 2 yr, 67P/Churyumov-Gerasimenko (67P), a Jupiter family comet. Here, we report 67P composition focusing on elements C O. It has high (atomic |${\rm{C}}/{\rm{Si}} =...
Samples of the carbonaceous asteroid Ryugu were brought to Earth by Hayabusa2 spacecraft. We analyzed 17 samples measuring 1 8 millimeters. Carbon dioxide-bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu's parent formed in outer Solar System. The contain low abundances materials at high temperatures, such as chondrules and calcium- aluminum-rich inclusions. rich phyllosilicates carbonates, which through aqueous alteration reactions temperature, pH,...
Samples of the carbonaceous asteroid (162173) Ryugu were collected and brought to Earth by Hayabusa2 spacecraft. We investigated macromolecular organic matter in samples found that it contains aromatic aliphatic carbon, ketone, carboxyl functional groups. The spectroscopic features are consistent with those chemically primitive chondrite meteorites experienced parent-body aqueous alteration (reactions liquid water). morphology carbon includes nanoglobules diffuse associated phyllosilicate...
Abstract— Due to their small size, the mineralogical and chemical properties of micrometeorites (MMs) are not representative parent bodies on centimeter meter scales that used define body groups through petrological study meteorites. Identifying which MM derived from same type is problematic requires particles be rigorously grouped basis mineralogical, textural, reflect fundamental genetic differences between meteorite bodies, albeit with minimal bias towards preconceived models....
Primitive interplanetary dust is expected to contain the earliest solar system components, including minerals and organic matter. We have recovered, from central Antarctic snow, ultracarbonaceous micrometeorites whose matter contains extreme deuterium (D) excesses (10 30 times terrestrial values), extending over hundreds of square micrometers. identified crystalline embedded in micrometeorite matter, which suggests that this reservoir could formed within itself rather than having direct...
ABSTRACT The COmetary Secondary Ion Mass Analyser instrument on board ESA's Rosetta mission has collected dust particles in the coma of comet 67P/Churyumov–Gerasimenko. During early-orbit phase mission, and particle agglomerates have been imaged analyzed inner at distances between 100 km 10 off cometary nucleus more than 3 AU from Sun. We identified 585 14 μ m size. are low impact speeds constitute a sample impacting fragmenting targets. sizes range up to sub-millimeter differential flux...
The properties of the smallest subunits cometary dust contain information on their origin and clues to formation planetesimals planets. Compared IDPs or particles collected during Stardust mission, in coma comet 67P/Churyumov-Gerasimenko Rosetta mission provides a resource minimally altered material with known whose structural can be used further investigation our early Solar System. A novel method is presented achieve highest spatial resolution imaging possible MIDAS Atomic Force Microscope...
The annual flux of extraterrestrial material on Earth is largely dominated by sub-millimetre particles. mass distribution and absolute value this cosmic dust at the Earth's surface however still uncertain due to difficulty in monitoring both collection efficiency exposure parameter (i.e. area-time product m2.yr). In paper, we present results from micrometeorite collections originating vicinity CONCORDIA Station located Dome C (Antarctica), where performed several independent melts large...
Abstract Massive stars disrupt their natal molecular cloud material through radiative and mechanical feedback processes. These processes have profound effects on the evolution of interstellar matter in our Galaxy throughout universe, from era vigorous star formation at redshifts 1–3 to present day. The dominant can be probed by observations Photo-Dissociation Regions (PDRs) where far-ultraviolet photons massive create warm regions gas dust neutral atomic gas. PDR emission provides a unique...
Most low-mass stars form in stellar clusters that also contain massive stars, which are sources of far-ultraviolet (FUV) radiation. Theoretical models predict this FUV radiation produces photodissociation regions (PDRs) on the surfaces protoplanetary disks around affects planet formation within disks. We report James Webb Space Telescope and Atacama Large Millimeter Array observations a FUV-irradiated disk Orion Nebula. Emission lines detected from PDR; modeling their kinematics excitation...
Abstract Transmission electron microscopy analyses of Hayabusa2 samples show that Ryugu organic matter exhibits a range morphologies, elemental compositions, and carbon functional chemistries consistent with those carbonaceous chondrites have experienced low‐temperature aqueous alteration. Both nanoglobules diffuse are abundant. Non‐globular particles also present, including some contain nanodiamond clusters. Diffuse is finely distributed in around phyllosilicates, forms coatings on other...
Context. A 3.4 μm absorption band (around 2900 cm-1), assigned to aliphatic C-H stretching modes of hydrogenated amorphous carbons (a-C:H), is widely observed in the diffuse interstellar medium, but disappears or modified dense clouds. This spectral difference between different phases medium reflects processing dust environments. Cosmic ray bombardment one processes that make carbonaceous evolve.
Aims. The goal of this study is to simulate space weathering processes on primitive bodies. We use ion implantation as a simulation solar wind irradiation, which has been suggested by several authors be the major component main belt asteroids. laboratory analogs we irradiate and analyze are carbonaceous chondrites; started with Allende CV meteorite in companion paper present results Murchison CM meteorite.