Voyager 2 flew so far below the plane of the solar system after Neptune that only one antenna on Earth can still send it commands, a 70-metre dish outside Canberra, which went offline for eleven months of repairs in 2020 while the spacecraft flew on in silence, unable to be told anything.

Voyager 2 flew so far below the plane of the solar system after Neptune that only one antenna on Earth can still send it commands, a 70-metre dish outside Canberra, which went offline for eleven months of repairs in 2020 while the spacecraft flew on in silence, unable to be told anything.

Voyager 2’s last encounter with a planet did more than complete the only close reconnaissance of Neptune and Triton. It also fixed the spacecraft on a path that made one antenna outside Canberra uniquely important to the rest of its mission. After passing over Neptune’s north pole in August 1989, Voyager 2 was deflected south. It is now escaping at an angle of about 48 degrees below the ecliptic, the broad plane in which the planets orbit. From …