Spotlight

Mercury magnetospheric orbiter mio

Mercury has a unique and complex space environment with its weak global magnetic field, intense solar wind, tenuous exosphere, and magnetospheric plasma particles. This complex system makes Mercury an excellent scientific target to understand the effects of the solar wind on planetary environments. Besides, investigating Mercury’s dynamic magnetosphere also plays a key role to understand the extreme exoplanetary environment and its habitability conditions against strong stellar winds. BepiColombo, a joint mission to Mercury by the European Space Agency and Japan Aerospace Exploration Agency, will address remaining open questions using two spacecraft, Mio and the Mercury Planetary Orbiter. Mio is a spin-stabilized spacecraft designed to investigate Mercury’s space environment, with a powerful suite of plasma instruments, a spectral imager for the exosphere, and a dust monitor. After the successful launch and the commissioning activities, Mio started science observations even during the interplanetary cruise phase. The Earth flyby and the first Venus flyby were completed on 10 April 2020 and on 15 October 2020, respectively. During the two flybys, science observations are performed and plasma instruments successfully measured both the Earth’s magnetosphere and Venus’s induced magnetosphere. Solar wind observations during the cruise were also performed by the electron sensors onboard Mio. We studied the opportunities of joint observations with other spacecraft such as NASA’s Parker Solar Probe and ESA’s Solar Orbiter and planned some coordination campaigns. Here we present the overview, science goals, updated status, initial results during the cruise, and the upcoming observation plans of BepiColombo/Mio.