Scientists therefore want to better understand what goes on when the solar wind, made up of protons and electrons, strikes the magnetosphere. The interaction is known to push the magnetosphere into a teardrop shape that extends beyond the Moon on Earth's nightside. When the solar wind whips up a strong storm, it can knock out radio communications, disrupt satellites and even threaten power grids on Earth. So researchers used the satellite's ultraviolet imager to peer inside Earth's magnetosphere. They studied a region of space full of ionized gas, created when atoms lose electrons.
Scientists call the stuff plasma.
It is known to interact with the solar wind , but images of the interaction have been elusive. The new study, led by James Burch of the Southwest Research Institute, produced the first global images of this region of space known as Earth's plasmasphere. The results are reported in the Jan. 26 issue of the journal Science . Burch and his colleagues discovered that during strong solar storms, a buildup of plasma, described as a shoulder, forms on the side of the Earth facing the storm. On Earth's backside, the plasma is pulled into a long tail that curves out into space and points back toward the Sun.