Energetic neutral atom (ENA) imaging, often described as "seeing with atoms", is a technology used to create global images of otherwise invisible phenomena in the magnetospheres of planets and throughout the heliosphere, even to its outer boundary.This constitutes the far-flung edge of the solar system. Although ENAs were observed in space from the 1960s through 1980s, the first dedicated ENA camera was not flown until 1995 on the Swedish Astrid-1 satellite, to study Earth's magnetosphere.