(Left) This first-light image from EUV is the first complete picture of Earth's plasmasphere ever taken. The white circle shows the approximate position and size of Earth. Outside the circle, emissions from singly-ionized helium in Earth's plasmasphere extend outward to several Earth radii. Because the emission is stimulated by sunlight, ions in Earth's shadow are not visible; the shadow is the darker region marked by the white line. This image was recorded at 03:20 GMT on May 4, 2000, when IMAGE was at a range of 36,664 km from the center of Earth and above a latitude of 80 N. It is a composite made by joining images from the three EUV sensor heads. The two vertical dark stripes where the sections are joined will be corrected in later processing.
(Right) A second image, acquired by EUV on May 7, shows small-scale structure (white arrow) in the evening sector of the plasmasphere. The investigation of such structures and of the dynamic interaction between the plasmasphere and the sunward-flowing magnetotail plasma is one of the key objectives of the EUV investigation. This second image was obtained when the spacecraft at a distance of 35921 km from the Earth's center and above 77 degrees north latitude.
Credit: B. Sandel and T. Forrester, Univ. of Arizona