Debris strewn from the tail of many comets make up a disk of dust around the Sun, in the ecliptic plane where the planets orbit. It scatters sunlight and it is sometimes visible at twilight on the Earth, as the Zodiacal Light. Image processing has to subtract its effect precisely, to bring the solar wind and the Milky Way into plain view. Random flashes of light in the images are due to cosmic rays striking the detector. These should be regarded, not as blemishes, but as part of scenery.
Cosmic rays are energetic particles coming from exploded stars in the universe.
Variations in the interplanetary magnetic field influence their intensity in the vicinity of SOHO and the Earth. Operating beyond the Earth's magnetic field, which repels most of the cosmic ray particles, SOHO is more exposed to the cosmic rays. The Naval Research Laboratory is the Department of the Navy's corporate laboratory. NRL conducts a broad program of scientific research, technology and advanced development.