Earth Planets Space, Vol. 60 (No. 4), pp. 407-416, 2008
I. Yoshikawa1, A. Yamazaki2, G. Murakami1, K. Yoshioka1, S. Kameda2, F. Ezawa1, T. Toyota1, W. Miyake3, M. Taguchi4, M. Kikuchi4, and M. Nakamura2
1Department of Earth and Planetary Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
2Institute of Space and Astronautical Science, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510, Japan
3National Institute of Information and Communications Technology, 4-2-1 Nukuikita-machi, Koganei, Tokyo 184-8795, Japan
4National Institute of Polar Research, 9-10-1, Kaga, Itabashi, Tokyo 173-8515, Japan
(Received April 16, 2007; Revised August 22, 2007; Accepted November 5, 2007; Online published April 9, 2008)
The Upper Atmosphere and Plasma Imager (UPI) is to be launched in 2007 and sent to the Moon. From the lunar orbit, two telescopes are to be directed towards the Earth. The Moon has no atmosphere, which results in there being no active emission near the spacecraft; consequently, we will have a high-quality image of the near-Earth environment. As the Moon orbits the Earth once a month, the Earth will also be observed from many different directions. This is called a "science from the Moon". The two telescopes are mounted on a two-axis gimbal system, the Telescope of Extreme ultraviolet (TEX) and Telescope of Visible light (TVIS). TEX detects the O II (83.4 nm) and He II (30.4 nm) emissions scattered by ionized oxygen and helium, respectively. The targets of extreme-ultraviolet (EUV) imaging are the polar ionosphere, the polar wind, and the plasmasphere and inner magnetosphere. The maximum spatial and time resolutions are 0.09 Re and 1 min, respectively.
Key words: EUV, plasmasphere, polar wind, imaging, remote-sensing, SELENE.