The spacecraft Voyager 1 is now nearly 18 billion kilometres from the sun, at the very end of the solar system. It’s peacefully sailing in a new region between us and interstellar space. NASA poetically calls it cosmic purgatory.
The cosmic purgatory is not full of souls wandering in angst. At least, Voyager 1 doesn’t have any instrument to register these. But it has other instruments to measure more material things, like solar particles, magnetic fields and cosmic rays.
Using its Low Energy Charged Particle instrument, Cosmic Ray Subsystem and Magnetometer Voyager 1 has been collecting data for the past year, showing that there’s no solar wind going either way. Like in the Earth’s oceans doldrums, space here is serene, unperturbed.
This stagnation region is an area in which “the wind of charged particles streaming out from our sun has calmed, our solar system’s magnetic field has piled up, and higher-energy particles from inside our solar system appear to be leaking out into interstellar space.” Like a body, this is the skin of our solar system.
Soon, Voyager will pass through this cosmic purgatory and reach true interstellar space. According to Ed Stone, Voyager project scientist at the California Institute of Technology in Pasadena, “Voyager is showing that what is outside is pushing back. We shouldn’t have long to wait to find out what the space between stars is really like.”
It’s been a long way since Voyager was launched in 1977. Steadily, she’s finally reaching her destination.
Be safe, Voyager.