Physics @ Berkeley
Events in Physics
Title: 290B Space Physics Seminar    (Seminar)
Start Date: 02/07/2006
Time: 1:45 pm
Location: 508-20 Evans
Speaker: Dr. Ronglan Xu & Dr. Lei Li
Affiliation: Center for Space Science and Applied Research, Chinese Academy of Science
Contact Person: Sam Lam   (510) 642-7297

Earth Plasmasphere EUV Imaging from the Chinese ChangE-2 Lunar Lander
Dr. Ronglan Xu & Dr. Lei Li
Center for Space Science and Applied Research, Chinese Academy of Sciences

The 2nd Chinese Lunar Program, Chang-E-2 (CE-2) mission will be launched around 2012. In this mission we will have an EUV Imager (EUVI) in the lander. The EUVI is similar to the imager on IMAGE satellite, but instead of a 30o conical field of view, here we need only 15o (Li and Xu to be published).

Since the spinning period of the Moon is equal to its rotation period, if the EUVI is installed toward the Earth initially, the field of view of EUVI may remain in the same direction, supposing that the orbit of the Moon around the Earth is a circular one. But the Moon moves around the Earth along an elliptic orbit with the mayor and minor axis equal to 384400 and 36330 km respectively, so the direction may have a small deviation of 0.044 degree per day. Moreover, the plane of the lunar orbit around the Earth has also a deviation of 6o41 from the Earth's ecliptic plane, so the direction may have a deviation of a few degrees. In order to keep the direction of the EUVI pointing toward center of the Earth, the view direction of EUVI should be adjusted each day by a pivoted platform. The EUVI will keep in a dormant state during night when the temperature of the lunar surface is low, and the solar radiation penetrates the entrance of the imager. So during each month, we will have almost 12 days' continuous image data of the Earth plasmasphere.

KuaFu (KF) Mission is proposed to be launched from 2012 2013, which consists of KF-A and B. The orbit of KF-A is around the first LaGrange point, and monitoring the parameter of the Sun. The orbit of KF B is similar to that of IMAGE. Here we propose a EUVI in KF-B, so that we can have simultaneously EUV observation of the Earth Plasmasphere from the top by KF B, and the side by CE-2. Using computer topography technique, we can estimate the global distribution of the density nij of He+ in the Earth plasmasphere, from the column densities of He+ in the plasmasphere observed by CE-2 and KF-B.