The spacecraft that refused to die. In nineteen seventy seven, NASA launched two probes designed to last five years. Forty seven years later, they are still transmitting data from beyond the edge of our solar system, and what they found there has rewritten everything scientists thought they knew about where our cosmic neighborhood ends.
Voyager one crossed the heliopause on August twenty fifth, two thousand twelve, becoming the first human made object to enter interstellar space. Voyager two followed in two thousand eighteen. Both spacecraft detected something no model had predicted: a wall of superheated plasma with temperatures reaching thirty thousand to fifty thousand kelvin, nearly ten times hotter than the surface of the sun. Scientists expected the boundary between solar wind and interstellar medium to be a quiet fade into cold darkness. Instead, they found fire.
The heliosphere, the bubble of plasma and magnetic field that the sun blows around itself, protects Earth from more than seventy percent of galactic cosmic radiation. The Voyagers mapped this protective boundary for the first time. They discovered that the heliopause breathes with the eleven year solar cycle. They found that magnetic fields inside and outside the boundary are mysteriously aligned. They revealed that particles leak through the boundary in ways no one anticipated.
Both spacecraft carry the Golden Record, a twelve inch gold plated copper disk containing one hundred fifteen images, greetings in fifty five languages, and ninety minutes of music from around the world. Designed by a committee chaired by Carl Sagan, the record is humanity’s message in a bottle, cast into the cosmic ocean with instructions for any intelligence that might someday find it drifting between the stars.
Credit to : The Calm Scientist
