Search Publications
Discrete aurora and the nightside ionosphere of Mars: an EMM–MEX conjunction of FUV imaging, ionospheric radar sounding, and suprathermal electron measurements
Holmström, Mats; Futaana, Yoshifumi; Harada, Yuki +7 more
Since 2021, a new surge in discrete aurora detections at Mars has been observed by the Emirates Mars Ultraviolet Spectrometer (EMUS) onboard the Emirates Mars Mission (EMM) Hope Orbiter as EMUS started to regularly obtain synoptic auroral images with a high sensitivity. Here we report on a fortuitous conjunction between EMM and Mars Express (MEX) …
Duskward displacement of plasmoids and reconnection in the near-Earth magnetotail
Miyashita, Yukinaga; Ieda, Akimasa
Magnetic reconnection in the near-Earth magnetotail is responsible for explosive release of energy during substorms and auroral breakups. This near-tail reconnection was previously assumed to occur around the midnight meridian, where earthward flows were typically observed. Based on observations of tailward-moving plasmoids, the Geotail spacecraft…
The pioneer Cluster mission: preparation of its legacy phase near re-entry
Escoubet, C. Philippe; Masson, Arnaud; Taylor, Matthew G. G. T. +5 more
The Cluster mission will always be the first ever multi-spacecraft mission mapping the Earth magnetosphere in three dimensions. Launched in 2000 and originally planned to operate for two years, it has been orbiting Earth for more than two solar cycles. Over the course of its lifetime, its data have enabled the scientific community to conduct pione…
High-resolution shape models of Phobos and Deimos from stereophotoclinometry
Barnouin, Olivier S.; Daly, R. Terik; Ernst, Carolyn M. +5 more
We created high-resolution shape models of Phobos and Deimos using stereophotoclinometry and united images from Viking Orbiter, Phobos 2, Mars Global Surveyor, Mars Express, and Mars Reconnaissance Orbiter into a single coregistered collection. The best-fit ellipsoid to the Phobos model has radii of (12.95 ± 0.04) km × (11.30 ± 0.04) km × (9.16 ± …
Heliocentric distance dependence of zodiacal light observed by Hayabusa2#
Tatsumi, Eri; Sugita, Seiji; Matsuura, Shuji +21 more
Zodiacal light (ZL) is sunlight scattered by interplanetary dust particles (IDPs) at optical wavelengths. The spatial distribution of IDPs in the Solar System may hold an important key to understanding the evolution of the Solar System and material transportation within it. The number density of IDPs can be expressed as
The Mars system revealed by the Martian Moons eXploration mission
Montmessin, Franck; Leblanc, François; Vandaele, Ann Carine +21 more
Japan Aerospace Exploration Agency (JAXA) plans a Phobos sample return mission (MMX: Martian Moons eXploration). In this study, we review the related works on the past climate of Mars, its evolution, and the present climate and weather to describe the scientific goals and strategies of the MMX mission regarding the evolution of the Martian surface…
The MMX rover: performing in situ surface investigations on Phobos
Michel, Patrick; Murdoch, Naomi; Zhang, Yun +22 more
The Japanese MMX sample return mission to Phobos by JAXA will carry a rover developed by CNES and DLR that will be deployed on Phobos to perform in situ analysis of the Martian moon's surface properties. Past images of the surface of Phobos show that it is covered by a layer of regolith. However, the mechanical and compositional properties of this…
Asymmetric deformation of the Earth's magnetosphere under low Alfvén Mach number solar wind: Observations and MHD simulation
Kasahara, Satoshi; Lavraud, Benoit; Saito, Yoshifumi +5 more
The density of the solar wind plasma near the Earth's magnetosphere sometimes decreases to only several per cent of the usual value, and such density extrema result in a significant reduction of the dynamic pressure and Alfvén Mach number (
Solar and geomagnetic activity dependence of 150-km echoes observed by the Equatorial Atmosphere Radar in Indonesia
Yokoyama, Tatsuhiro; Takagi, Rieko; Yamamoto, Mamoru
The occurrence characteristics of 150-km echoes in low-latitude regions are studied using the Equatorial Atmosphere Radar (EAR) in Indonesia. The long-term observation of the 150-km echoes by the EAR enables us to study the occurrence characteristics of 150-km echoes statistically. It is shown that the occurrence rate of the 150-km echoes observed…
Validation of coronal mass ejection arrival-time forecasts by magnetohydrodynamic simulations based on interplanetary scintillation observations
Tokumaru, Munetoshi; Fujiki, Ken'ichi; Shiota, Daikou +3 more
Coronal mass ejections (CMEs) cause various disturbances of the space environment; therefore, forecasting their arrival time is very important. However, forecasting accuracy is hindered by limited CME observations in interplanetary space. This study investigates the accuracy of CME arrival times at the Earth forecasted by three-dimensional (3D) ma…