NASA THEMIS All-Sky-Imagers (ASI) see the big picture of the Sun-Earth connection

A collection of ground-based All-Sky Imagers (ASI) makes an important component of the THEMIS mission in understanding the interaction of the invisible magnetosphere and the aurora, the only part we can see with our eyes. These ground-based observatories, sometimes referred to as the sixth THEMIS satellite, also have sensitive magnetometers and thus are critical to piecing together the Earth-side of the space weather puzzle. Descriptions of the instruments are available on the THEMIS webpage: http://themi