  This review summarizes the research of Mercury's magnetosphere in the
Post-MESSENGER era and compares its dynamics to those in other planetary
magnetospheres, especially to those in Earth's magnetosphere. This review
starts by introducing the planet Mercury, including its interplanetary
environment, magnetosphere, exosphere, and conducting core. The frequent and
intense magnetic reconnection on the dayside magnetopause, which is represented
by the flux transfer event "shower", is reviewed on how they depend on
magnetosheath plasma beta and magnetic shear angle across the magnetopause,
following by how they contribute to the flux circulation and
magnetosphere-surface-exosphere coupling. In the next, the progress of
Mercury's magnetosphere under extreme solar events, including the core
induction and the reconnection erosion on the dayside magnetosphere, the
responses of the nightside magnetosphere, are reviewed. Then, the dawn-dusk
properties of the plasma sheet, including the features of the ions, the
structure of the current sheet, and the dynamics of magnetic reconnection, are
summarized. The last topic reviews the particle energization in Mercury's
magnetosphere, which includes the energization of the Kelvin-Helmholtz waves on
the magnetopause boundaries, reconnection-generated magnetic structures, and
the cross-tail electric field. In each chapter, the last section discusses the
open questions related with each topic, which can be considered by the
simulations and the future spacecraft mission. We close by summarizing the
future BepiColombo opportunities, which is a joint mission between ESA and
JAXA, and is en route to Mercury.
