NASA sports a heliophysics fleet of more than 20 spacecraft to study the dynamic electromagnetic system stretching from the sun to Earth.
Space around Earth is anything but a barren vacuum. The area seethes with constantly changing electric and magnetic fields. Charged particles move energy around, create electric currents, produce the aurora, and sometimes even damage technology in space. Many of these particles stream in from the solar wind and travel 93 million miles from the surface of the sun. Other areas are dominated by particles of a more local source: Earth's atmosphere. This entire electromagnetic environment, from the sun to the edges of the solar system, is known as the heliosphere. As illustrated in the visualization below, a fleet of NASA spacecraft—some orbiting tightly around Earth, some closer to the sun, and two almost to the edge of the solar system—try to understand this complex, dynamic system. Using all of these resources together, researchers will learn how to predict changes in space weather and protect spacecraft and astronauts from this harsh environment.