Speaker: Prof. Yoshifumi Saito (Institute of Space and Astronautical Science)

September. 18^th, 2024

4pm, Beijing time

We have the pleasure to host the next Infinite Horizons’ seminar on September 18th, 2024. Our host will be Prof. Yoshifumi Saito from the Institute of Space and Astronautical Science. Prof. Saito will talk about Plasma Environment around Moon and Mercury - Observations from Kaguya and Bepi/Colombo/Mio.

Seminar's Abstract: 
Solar wind is constantly blowing out from the sun. It reaches the celestial bodies in our solar system and creates the surrounding environment of the celestial bodies with various characteristics. These environments around celestial bodies are constantly changing according to the condition of the solar wind and that around the celestial bodies, creating a dynamic environment around the them. Among these various celestial bodies, we have been focusing on the airless bodies for the past quarter century. The Earth's Moon has neither thick atmosphere nor a global intrinsic magnetic field, so the solar wind directly impacts the Moon's surface. The impact of solar wind plasma on the surface causes the material on the lunar surface to be sputtered out to the surroundings and also causes some of the solar wind plasma impacted on the surface to be back scattered. Furthermore, although there is no global intrinsic magnetic field on the Moon, there are numerous magnetic anomalies on the lunar surface, and when solar wind plasma collides with them, a "mini-magnetosphere" is formed. These lunar environments were observed at altitudes of less than 100 km above the lunar surface for two years between 2007 and 2009 by Kaguya, which equipped with the MAP-PACE instrument to measure "in-situ" plasma around the Moon. On the other hand, Mercury, which is located closest to the Sun in the solar system, has no atmosphere but has a global intrinsic magnetic field.In order to understand the universal characteristics of the airless bodies, it is desirable to observe both objects with and without intrinsic magnetic fields at the same level. Following Kaguya's exploration of the Moon, we had the opportunity to send the BepiColmbo/Mio spacecraft with the MPPE plasma instrument to Mercury. BepiColmbo/Mio will arrive at Mercury in November 2026 after eight-year cruising to the planet. This lecture will present the results to date and future plans for a quarter of a century of research on airless bodies.

Zoom ID: 854 1065 5635
Livestream Link: http://live.bilibili.com/22671469
(Our Infinite Horizons seminars are usually host on the third Wednesday of the month)

About the speaker: 

Prof. Yoshifumi Saito got his Doctor’s Degree in Science in 1995 at the University of Tokyo. His research activities have been related to rocket and satellite experiments for study of space plasmas in the ionosphere and magnetosphere. He has taken part in the development of the space-borne instruments for hot plasma and low-energy particle measurements. Based on the obtained data by the rocket and satellite experiments, he has conducted many researches on elementary processes for transport and acceleration of charged particles in the space plasmas and the global electrodynamics of the magnetospheric plasmas. Since 2017, he has been a professor at the Institute of Space and Astronautical Science, and starting from 2018, he has taken the role of Director of Department of Solar System Sciences, at ISAS.