Real-time analysis of humanity's most distant spacecraft
The magnetometer is Voyager's compass — and it's the instrument that closed the case. When Voyager crossed into interstellar space, the plasma wave instrument heard the change and the density measurements confirmed it. But it was the magnetometer that mapped the direction of the magnetic field and proved that Voyager was embedded in a fundamentally different magnetic environment: no longer the Sun's field, dragged outward by the solar wind, but the galactic magnetic field of the Milky Way itself.
What I find remarkable is the scale of what we're measuring. The interstellar magnetic field around Voyager is roughly 0.4–0.5 nanotesla. A refrigerator magnet is about 5 millitesla — that's ten million times stronger. Voyager is detecting a whisper of magnetism from across the galaxy, using an instrument built nearly five decades ago. Every data point on the chart below is a small miracle of engineering sensitivity.
This is the final chapter of the Voyager instrument story: trajectory tells you where, plasma waves tell you what it sounds like, density tells you what it's made of, and the magnetometer tells you which way the cosmic wind blows. Together, they paint a complete portrait of what it means to leave the solar system.
Voyager 1, launched on September 5, 1977, is currently humanity's most distant artificial object, traveling through interstellar space at over 160 AU from the Sun. This dashboard provides real-time analysis of its position and magnetic field measurements from NASA's archives.