A vast region

NASA’s Voyager spacecraft revealed a remarkable discovery at the edge of our solar system: a vast region of superheated plasma, reaching temperatures between 30,000 and 50,000 Kelvin.
This area, encountered by both Voyager 1 and Voyager 2 as they crossed the heliopause, the boundary where the solar wind is stopped by the pressure of interstellar space, is sometimes referred to as a “wall of fire.”
Despite these extreme temperatures, the region poses no danger to the spacecraft because of its incredibly low particle density; the high temperatures reflect particle speed, not heat felt as we experience it.
Scientists believe this heat is caused by plasma compression and magnetic reconnection, where magnetic fields release large amounts of energy. Voyager’s findings revealed that the boundary of the heliosphere is far more complex and energetic than previously thought.
Even decades after their launch, the Voyager probes continue to offer groundbreaking insights into the dynamic and mysterious frontier between our solar system and interstellar space.