A5040715153- Astro and Planetary Science
- Planetary Science and Exploration
- Geology and Paleoclimatology Research
- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Space Science and Extraterrestrial Life
- Space Exploration and Technology
- Spacecraft and Cryogenic Technologies
- Marine and environmental studies
- Spaceflight effects on biology
- Fluid Dynamics Simulations and Interactions
- Space exploration and regulation
- Isotope Analysis in Ecology
- Space Satellite Systems and Control
- Geological and Geochemical Analysis
- Geomagnetism and Paleomagnetism Studies
- earthquake and tectonic studies
- Slime Mold and Myxomycetes Research
- Spacecraft Design and Technology
- Fluid Dynamics and Vibration Analysis
- Spacecraft Dynamics and Control
- Geological formations and processes
- Methane Hydrates and Related Phenomena
- Mercury impact and mitigation studies
- Law, logistics, and international trade
National Sagamihara Hospital
2019-2024
Japan Aerospace Exploration Agency
2021-2024
Institute of Space and Astronautical Science
2021-2023
Life Science Institute
2016-2021
Tokyo Institute of Technology
2017-2021
Earth-Life Science Institute
2016-2020
International Society of Automation
2020
Université Paris Cité
2016-2017
Institut de physique du globe de Paris
2015-2017
Centre National de la Recherche Scientifique
2017
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,...
The hypothesis of a recent origin Saturn's rings and its mid-sized moons is actively debated. It was suggested that proto-Rhea proto-Dione might have collided recently, giving birth to the modern system moons. also rapid viscous spreading debris may implanted mass inside Roche limit, ring system. However, this scenario has been only investigated in very simplified way for moment. This paper investigates it detail assess plausibility by using $N$-body simulations analytical arguments. When...
Phobos and Deimos are the two small Martian moons, orbiting almost on equatorial plane of Mars. Recent works have shown that they can accrete within an impact-generated inner dense outer light disk, same impact potentially forms Borealis basin, a large northern hemisphere basin current However, there is no priori reason for to take place close north pole (Borealis present location) nor generate debris disk in Mars (in which orbit). In this paper, we investigate these remaining issues giant...
Phobos and Deimos are the two small moons of Mars. Recent works have shown that they can accrete within an impact-generated disk. However, detailed structure initial thermodynamic properties disk poorly understood. In this paper, we perform high-resolution SPH simulations Martian moon-forming giant impact also form Borealis basin. This heats up material (around $\sim 2000$ K in temperature) with entropy increase 1500$ J K$^{-1}$ kg$^{-1}$. Thus, should be mostly molten, though a tiny...
Context. Pressure maxima are regions in protoplanetary disks which pebbles can be trapped because the have no local pressure gradient. These could ideal places planetesimals might formed or to isotopic reservoirs isolated. Observations of show that dusty ring structures common, and sometimes invoked as a possible explanation. In our Solar System, bumps been suggested mechanism for separating with different nucleosynthetic compositions identified among chondrites iron meteorites. this paper,...
Circumplanetary particle disks would be created in the late stage of planetary formation either by impacts bodies or disruption satellites passing bodies, and can formed accretion disk particles spreading across Roche limit. Previous N-body simulation lunar focused on single-satellite systems from with large disk-to-planet mass ratios, while recent models multiple-satellite smaller ratios do not take account gravitational interaction between satellites. In present work, we investigate...
Abstract The MMX infrared spectrometer (MIRS) is an imaging onboard JAXA mission. (Martian Moon eXploration) scheduled to be launched in 2024 with sample return Earth 2029. MIRS built at LESIA-Paris Observatory collaboration four other French laboratories, and financial support of CNES close MELCO. instrument designed fully accomplish MMX’s scientific measurement objectives. will remotely provide near-infrared spectral maps Phobos Deimos containing compositional diagnostic features that used...
Abstract Top-shaped asteroids have been observed among near-Earth asteroids. About half of them are reported to moons (on the order ∼1 wt.% top-shaped primary) and many an equatorial ridge. A recent study has shown that enigmatic figure (e.g., Ryugu, Bennu, Didymos) could result from axisymmetric landslide primary during a fast spin-up near breakup rotation period. Such would inevitably form particulate disk around asteroid with short timescale (∼3 hr). However, long-term full dynamical...
Abstract Recent works have shown that the Martian moons Phobos and Deimos may accreted within a giant impact-generated disk whose composition is about an equal mixture of material impactor material. Just after impact, surface heated up to ∼3000–6000 K building blocks moons, including volatile-rich vapor, were ∼2000 K. In this paper, we investigate volatile loss from by hydrodynamic escape vapor radiation pressure on condensed particles. We show non-negligible amount volatiles (>10% with...
ABSTRACT Centaurs are minor planets orbiting between Jupiter and Neptune that have or had crossing orbits with one more giant planets. Recent observations reinterpretation of previous revealed the existence ring systems around 10199 Chariklo 2060 Chiron. However, origin such a planet is still an open question. Here, we propose tidal disruption differentiated object experiences close encounter could naturally form diverse ring–satellite Centaurs. During encounter, icy mantle passing...
Context. When and where planetesimals form in a protoplanetary disk are highly debated questions. Streaming instability is considered the most promising mechanism, but conditions for its onset stringent. Disk studies show that planet forming region not turbulent because of lack ionization possibly dead zones (DZs). Aims. We investigate planetesimal formation an evolving disk, including DZ thermal evolution. Methods. used 1D time-evolving stratified model with composite chemistry grains, gas...
Sample-return missions will look for extraterrestrial life and biomarkers on Mars Phobos
Around the snow line, icy pebbles and silicate dust may locally pile-up form rocky planetesimals via streaming instability and/or gravitational instability. We perform 1D diffusion-advection simulations that include back-reaction to radial drift diffusion of dust, ice sublimation, release their recycling through recondensation sticking onto outside line. use a realistic description scale height obtained from Ida et al. including effects Kelvin-Helmholtz study dependence solid on distinct...
Asteroid 162173 Ryugu and asteroid 101955 Bennu, which were recently visited by spacecraft Hayabusa2 OSIRIS-REx, respectively, are spinning top-shaped rubble piles. Other axisymmetric near-Earth asteroids have been observed with ground-based radar, most of rotate near breakup rotation periods ∼3 h. This suggests that rotation-induced deformation through rotational spinup produces top shapes. Although some previous simulations using the Discrete Element Method showed piles may produce oblate...
Abstract Phobos is the target of return sample mission Martian Moons eXploration by JAXA that will analyze in great detail physical and compositional properties satellite from orbit, surface, terrestrial laboratories, giving clues about its formation. Some models propose Deimos were formed after a giant impact rise to an extended debris disk. Assuming cascade disruptions reaccretions several parent bodies this disk, they are all characterized low material cohesion, Hesselbrock & Minton...
The degree of disruption in collisions free space is determined by specific impact energy, and the mass fraction largest remnant a monotonically decreasing function energy. However, it has not been shown whether such relationship applicable to under influence planet's tidal force, which important ring dynamics satellite accretion. Here we examine collisional gravitational aggregates environment using local N-body simulations. We find that outcomes collision largely depend on velocity,...
Context. The formation of rocky planetesimals is a long-standing problem in planet theory. One the possibilities that it results from gravitational instability as result pile-up small silicate dust particles released sublimating icy pebbles pass snow line. Aims. We want to understand and quantify role water line for rock-rich ice-rich planetesimals. In this paper, we focus on A companion paper examines combined both Methods. developed new Monte Carlo code calculate radial evolution turbulent...
Asteroid exploration has been attracting more attention in recent years. Nevertheless, we have just visited tens of asteroids while discovered than one million bodies. As our current observation and knowledge should be biased, it is essential to explore multiple directly better understand the remains planetary building materials. One mission design solutions utilizing asteroid flyby cycler trajectories with Earth gravity assists. An trajectory problem a subclass global optimization problems...