| Abstract |
Mercury has a thin atmosphere. Though the pressure at the surface is < ~10^-12 atm, the atmospheric sodium emission can be detected using the ground-based telescope. The suggested source process of sodium is photon-stimulated desorption, solar wind sputtering, and micrometeoride vaporization. After released from the surface, sodium atoms are ionized and lost to the interplanetary space in 1-3 hours. In this study, we discuss the environment of Mercury based on the result of ground-based observation of Mercury's sodium. Additionally, MESSENGER and BepiColombo project will be introduced. |
