A5054965366- Planetary Science and Exploration
- Astro and Planetary Science
- Space Exploration and Technology
- Space Science and Extraterrestrial Life
- Solar and Space Plasma Dynamics
- Ionosphere and magnetosphere dynamics
- Space exploration and regulation
- Spaceflight effects on biology
- Atmospheric Ozone and Climate
- Geophysics and Gravity Measurements
- X-ray Diffraction in Crystallography
- Atmospheric and Environmental Gas Dynamics
- Crystallization and Solubility Studies
- Spacecraft Design and Technology
- Geology and Paleoclimatology Research
- Calibration and Measurement Techniques
- Scientific Research and Discoveries
- Atmospheric aerosols and clouds
- Physics of Superconductivity and Magnetism
- Geomagnetism and Paleomagnetism Studies
- Stellar, planetary, and galactic studies
- Crystallography and molecular interactions
- Surface and Thin Film Phenomena
- Spectroscopy and Laser Applications
- Space Satellite Systems and Control
The University of Tokyo
2016-2025
Tokyo University of Information Sciences
2017-2021
Frontier Science Foundation
2017-2020
Grieg Seafood (Norway)
2019
National Sagamihara Hospital
2011-2017
Japan Aerospace Exploration Agency
2006-2016
Institute of Space and Astronautical Science
2007-2016
Toshiba (Japan)
2013-2016
International Society of Automation
2014
Matsumoto Livestock Hygiene Service Center
2012
Abstract Martian moons exploration, MMX, is the new sample return mission planned by Japan Aerospace Exploration Agency (JAXA) targeting two with scheduled launch in 2024 and to Earth 2029. The major scientific objectives of this are determine origin Phobos Deimos, elucidate early Solar System evolution terms volatile delivery across snow line terrestrial planets having habitable surface environments, explore evolutionary processes both Mars environment. To achieve these objectives, during a...
AKATSUKI is the Japanese Venus Climate Orbiter that was designed to investigate climate system of Venus. The orbiter launched on May 21, 2010, and it reached December 7, 2010. Thrust applied by orbital maneuver engine in an attempt put into a westward equatorial orbit around with 30-h period. However, this operation failed because malfunction propulsion system. After failure, spacecraft orbited Sun for 5 years. On 2015, once again approached insertion successful, whereby apoapsis ~440,000 km...
After the arrival of Akatsuki spacecraft Japan Aerospace Exploration Agency at Venus in December 2015, radio occultation experiment, termed RS (Radio Science), obtained 19 vertical profiles Venusian atmosphere by April 2017. An onboard ultra-stable oscillator is used to generate stable X-band downlink signals needed for experiment. The quantities be retrieved are atmospheric pressure, temperature, sulfuric acid vapor mixing ratio, and electron density. Temperature were successfully down ~ 38...
We present observational evidence of the variation cloud‐tracked zonal velocity by ~20 m s –1 with a timescale few hundred days in southern low latitude region based on an analysis cloud images taken Venus Monitoring Camera board Express. A spectral suggests that has periodicity period about 255 days. Although features are not always passive tracers, periodical dynamical state is robust feature. Superposed this long‐term velocity, Kelvin wave‐like disturbances tend to be observed periods...
The thermal infrared imager TIR onboard Hayabusa2 has been developed to investigate thermo-physical properties of C-type, near-Earth asteroid 162173 Ryugu. is one the remote science instruments on designed understand nature a volatile-rich solar system small body, but it also significant mission objectives provide information surface physical and conditions for sampling site selection as well assessment safe landing operations. based two-dimensional uncooled micro-bolometer array inherited...
Venus is covered with thick clouds. Ultraviolet (UV) images at 0.3–0.4 microns show detailed cloud features the cloud-top level about 70 km, which are created by an unknown UV-absorbing substance. Images acquired in this wavelength range have traditionally been used to measure winds top. In study, we report low-latitude obtained from taken UV imager, UVI, onboard Akatsuki orbiter December 2015 March 2017. UVI provides two filters centered 365 and 283 nm. While 365-nm enable continuation of...
Explaining super-rotation on Venus The solid surface of rotates very slowly, once every 243 days, but its thick atmosphere circles the planet in just 4 days. This phenomenon, known as super-rotation, requires a continuous input angular momentum, from an unknown source, to overcome friction with surface. Horinouchi et al. mapped planet's winds using ultraviolet observations Venus' clouds orbiting Akatsuki spacecraft (see Perspective by Lebonnois). They incorporated these data into global...
The Akatsuki spacecraft of Japan was launched on May 21, 2010. planned to enter a Venus-encircling near-equatorial orbit in December 7, 2010; however, the Venus insertion maneuver has failed, and at present is orbiting Sun. There possibility conducting an again several years later. main goal mission understand Venusian atmospheric dynamics cloud physics, with explorations ground surface interplanetary dust also being themes. angular motion roughly synchronized zonal flow near base for 20...
Abstract The existence of large stationary gravity waves was discovered during Akatsuki's first observation sequence in 2015. In this study, the further detection brightness temperature images over a 1.5 year period is reported. periodically appeared mostly above four specific highland regions low latitudes when these were local afternoon. wave amplitudes attenuated after locations passed beyond evening terminator, and tended to slowly drift eastward their lifetimes. appearances depend not...
Abstract We present distributions of the zonal-mean temperature and static stability in Venusian atmosphere obtained from Venus Express Akatsuki radio occultation profiles penetrating down to an altitude 40 km. At latitudes equatorward 75°, derived observed is consistent with previous in-situ measurements that there a low-stability layer at altitudes 50–58 km highly moderately stratified layers above 58 below 50 km, respectively. Meanwhile, poleward extends 42 which has been unreported...
Abstract The science operations of the spacecraft and remote sensing instruments for Martian Moon eXploration (MMX) mission are discussed by operation working team. In this paper, we describe Phobos observations during first 1.5 years spacecraft’s stay around Mars, Deimos before leaving system. observation, will be placed in low-altitude quasi-satellite orbits on equatorial plane make high-resolution topographic spectroscopic surface from five different altitudes orbits. also attempt to...
The Longwave Infrared Camera (LIR) is one of a suite cameras onboard the Venus orbiter Akatsuki. It will take images thermal radiation in wavelength range 8–12 µm emitted by cloud tops. use an uncooled micro-bolometer array as infrared image sensor makes LIR lightweight, small and low-power consumption instrument with required noise equivalent temperature difference 0.3 K. Temperature horizontal wind fields at cloud-top be retrieved for both dayside nightside equal quality. This provide key...
Radial variations of the amplitude and energy flux compressive waves in solar corona were explored for first time using a spacecraft radio occultation technique. By applying wavelet analysis to frequency series taken at heliocentric distances 1.5–20.5 RS (solar radii), quasi-periodic density disturbances detected almost all distances. The period ranges from 100 2000 s. fractional fluctuation increases with distance reaches ∼30% around 5 RS, implying that nonlinearity wave field is...
The ultraviolet imager (UVI) has been developed for the Akatsuki spacecraft (Venus Climate Orbiter mission). UVI takes (UV) images of solar radiation reflected by Venusian clouds with narrow bandpass filters centered at 283 and 365 nm wavelengths. There are absorption bands SO2 unknown absorbers in these wavelength regions. UV provide spatial distribution absorber around cloud top altitudes. also allow us to understand morphologies haze properties. Nominal sequential 2-h intervals used...
Radio scintillation observations have been unable to probe flow speeds in the low corona where scattering of radio waves is exceedingly strong. Here we estimate outflow continuously from vicinity Sun outer (heliocentric distances 1.5–20.5 solar radii) by applying strong theory scintillations for first time, using Akatsuki spacecraft as source. Small, nonzero were observed over a wide latitudinal range quiet-Sun corona, suggesting that supply plasma closed loops wind occurs an extended area....
Abstract Unlike the polar vortices observed in Earth, Mars and Titan atmospheres, Venus vortex is warmer than midlatitudes at cloud-top levels (∼65 km). This warm zonally surrounded by a cold latitude band located ∼60° latitude, which unique feature called ‘cold collar’ atmosphere. Although these structures have been numerous previous observations, formation mechanism still unknown. Here we perform numerical simulations of atmospheric circulation using general model, succeed reproducing...