Features of Foreshock Transients at Planetary Bow Shocks

— In front of the bow shock with a quasi-parallel configuration of the interplanetary magnetic field, there exists a region called a foreshock, in which many nonstationary processes take place, the largest of which are collectively named “foreshock transients.” The size of these formations can reach tens of Earth radii, which significantly influences the nature of the solar wind interaction with the magnetosphere. Some types of foreshock transients are also observed at other planets, including those without their own global magnetic field, which indicates the universality of these phenomena. This article lists the most well-known nonstationary processes occurring in the foreshock, as well as provides current ideas about the formation mechanisms of the largest foreshock transients.