Geotail is a joint ISAS (Japanese Institute of Space and Astronautical Science) and NASA mission to investigated Earth's magnetosphere and geomagnetic tail over distances of 8–200 Earth radii. Geotail's instruments continue to function, sending back information about how aurora form, how energy from the Sun funnels through near-Earth space, and the ways in which magnetic field lines move and rebound creating explosive bursts that rearrange the shape of our magnetic environment.