<italic>In situ</italic>measurements of the solar eruption

This work introduces a deep space mission of the great significance on the aspects of sciences and applications. Success of this mission will allow us to observe and detect the magnetic activities and the reconnection region occurring on a star at an unprecedentedly short distance by combining the remote sensing and the in situ approaches. First of all, we propose to access the core of the energy release region for the solar storm, namely the reconnecting current sheet, detecting and measuring fine structures and details of several important processes that include the magnetic diffusion, energy conversion, charged particle accelerations, and so on. Second, we shall perform the in situ measurement of components and distributions of the plasma and magnetic field inside the coronal mass ejection (CME, also known as the solar storm), helping us investigate and study the mechanism of CME and the original source of the plasma inside CME; detect the radio bursts caused by the energetic particles produced by reconnection in the current sheet and the CME-driven shock, collect these particles, and perform the in situ measurements of the CME-driven shock. Third, we shall measure the coronal magnetic field directly at the helio-distance ranging from 5$R_{\\rm~odot}$ to 10$R_{\\rm~odot}$, which is a key for looking into the energetics and dynamics of the solar eruption, and will further help as well resolve the problem of the corona heating, a century-long puzzle for solar physicists. Fourth, applying the method of imagining and spectroscopy, we are able to observe and study the dynamic process taking place in the high layer of the solar atmosphere with fairly high resolution. Usually, the highest resolution of observing the corona on the ground is around 1.5 arc-second ($1.5^{\\prime\\prime}$), and this value is lower in most of the cases, the in situ measurements at very short distance would enhance the resolution by a factor between 5 and 30. This will provide us an opportunity to study, look into, and understand the closest and the most important star to us at an unprecedentedly high level, and eventually help resolve the long-term problem and the puzzle like triggering of the solar eruption, magnetic reconnection, and corona heating. This is also a unique chance for us to look closely at or to perform the in situ measurement of the magnetic reconnection process taking place in the atmosphere of a star.