Hermean Magnetosphere and Exosphere

• Applicant: Dr. Daniel Heyner
• Subject Area: Astrophysics and Astronomy ; Geophysics
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 448674879

During the past decade the quality of experimental information on plasma and magnetic field structure in Mercury's magnetosphere has substantially improved. Since March 2011, when MESSENGER was inserted into the Mercury’s orbit and until April 30, 2015 when its mission was completed after 4104 orbits the spacecraft had transmitted approximately 14 TB of data, including magnetic field vector measurements. Nevertheless, many features of interaction of planetary magnetic fields with the solar wind plasma flow remain either unknown or clear only in general terms in the absence of reliable quantitative estimates. Among these, one can point out simple questions such as the relative magnitude of the interplanetary magnetic field penetrating the magnetosphere, the average magnitude and range of potential drop arising due to magnetized solar wind plasma flow past the planet, and conditions for formation, structure and relative length of the magnetotail on the nightside of the magnetosphere. The questions whether the planetary magnetic field slows down or accelerates the erosion of the exosphere and at what rate the exosphere is replenished with neutral particles sputtered from the surface remain open. Developing qualitative models of the Hermean magnetosphere and exosphere and refining it by comparing with the results of MESSENGER will allow our project to at least partially answer these questions.

• DFG Programme: Research Grants
• International Connection: Russia
• Partner Organisation: Russian Foundation for Basic Research
• Cooperation Partner: Dr. Igor Alexeev