On this date, Jan. 17, 2002, the Galileo probe made it’s 33 rd pass of Jupiter’s moon, Io. After Voyager 1’s pass in 1979, Io was dubbed the most volcanically active place in the solar system.

In October last year, during its 55th close flyby of the planet, Juno passed 7,270 miles (11,700 kilometers) from Io, making it the closest pass since NASA’s Galileo probe imaged the volcanic ...