"Nozomi" is Japan's first planetary mission and is launched on Jul. 4, 1998 from Kagoshima Space Center using M-V-3 launch vehicle. There are 14 scientific instruments onboard ﾒNozomiﾓ .They are including the instruments of U.S.A, Canada, Germany, and Sweden. "Nozomi" will investigate the interaction between upper atmosphere of Mars and solar wind. "Nozomi" is in Trans Mars orbit and will be inserted into Mars orbit on early 2004.
Helium ions near the Earth observed by the extreme ultra-violet telescope
Charged particles, which are called plasma, outflow from the Earth's ionosphere. Their motion is controlled by the Earth's dipole magnetic field. During a steady state of magnetic field disturbance the charged particles cannot escape to space. There is an outer boundary of average 4 Re position from the Earth (Re is a unit measured by Earth's radius), inside which the trapped charged particles exist.
About 90 percent of them is proton and the rest of them consists mainly helium ions. Particularly, helium ions resonantly scatter solar extreme ultra-violet lights. The extreme ultra-violet telescope onboard the Planet-B spacecraft detects these lights and create the image shown in Figure 1. (This is a picture taken from the evening side of the Earth.) Color-code represents the intensity of lights. Red indicates intense region and dense helium ions. Two curves in the figure represent dipole magnetic field lines that penetrate the equator at 4 Re away from the Earth. This observation clarifies that helium ions exist far away from the Earth over 10 Re, which is unexpected before.
"Nozomi" is Japan's first planetary mission and is launched on Jul. 4, 1998 from Kagoshima Space Center using M-V-3 launch vehicle. There are 14 scientific instruments onboard ﾒNozomiﾓ .They are including the instruments of U.S.A, Canada, Germany, and Sweden. "Nozomi" will investigate the interaction between upper atmosphere of Mars and solar wind. "Nozomi" is in Trans Mars orbit and will be inserted into Mars orbit on early 2004.