The Paradox of Plasma
Why 90,000°F Feels Like Nothing in Space How the Voyager spacecraft survived temperatures hotter than the surface of the sun—and what fluorescent bulbs can teach us about the fourth state of matter On August 25, 2012, NASA's Voyager 1 spacecraft accomplished something unprecedented: it became the first human-made object to leave our solar system. As it crossed the boundary between the sun's domain and the vast unknown of interstellar space, instruments measured temperatures reaching between 30,000 and 50,000 Kelvin—roughly 54,000 to 90,000 degrees Fahrenheit. Six years later, Voyager 2 followed, confirming measurements nearly double what models had predicted. Scientists dubbed this scorching boundary the "wall of fire." Yet neither spacecraft melted. Neither even warmed up measurably. Both continued their journeys into interstellar space, their 1970s-era electronics humming along, sending data back across billions of miles as if nothing remarkable had happened. ...