GEO-X : GEOSPACE X-RAY IMAGER

GEO-X (GEOspace X-ray imager) is a Japanese CubeSat project to be injected in the vicinity of the Moon. GEO-X aims X-ray imaging of the Earth’s dayside magnetospheric structures including cusps and magneto-sheaths. From past X-ray astronomy observations, charge exchange X-ray emission is observed between solar wind heavy ions (O⁷⁺, N⁵⁺, …) and neutrals in the Earth’s exosphere. Observational and simulation results strongly suggest that X-rays can be used for imaging of the Earth’s magnetosphere. For this purpose, a 12U CubeSat GEO-X is planned. It will carry a wide field of view X-ray imaging spectrometer composed of an ultra light-weight X-ray telescope and a high-speed Si sensor (Ezoe et al. 2018 J. Astron. Telescope Instrum., 4, 0406001). To observe the X-ray emission from the Earth’s magnetosphere, the satellite will be injected into a high Earth orbit. A launch time will be around the next solar maximum 2022-25.