Io

node

The innermost of Jupiter's four large moons, and the discovery that most changed what the Voyager tour was thought to be for. Before 1979 a body that size was expected to be geologically dead. On 8 March 1979, three days after Voyager 1's closest approach, the navigation engineer Linda Morabito was processing an over-exposed image taken to locate background stars when she noticed a crescent-shaped anomaly on Io's limb. It was an eruption plume rising hundreds of kilometres above the surface — the first active volcanism ever seen anywhere other than Earth. The heat source is tidal: Io is squeezed and released by Jupiter's gravity as its orbit is perturbed by Europa and Ganymede, and the resulting friction melts its interior. Not a place on Earth.

A node is not a place. Drawing it on a map would assert something about the world that no stored fact supports.