Helium observation in the Martian ionosphere by an X-ray ultraviolet scanner on Mars orbiter NOZOMI

We have built an X-ray ultraviolet (XUV) scanner on board Mars orbiter NOZOMI (Planet-B). This scanner has the He I and II emissions from the Martian atmosphere and ionosphere as its main target. These EUV emissions provide important information for the study of both Martian geological history and the interaction between solar wind and the Martian ionosphere. The XUV scanner will be operated in the parking orbit around the earth and also in the transfer orbit to Mars, where the terrestrial plasmasphere and interplanetary emissions will be studied.