April 25, 2022
On this date in 1983, Pioneer 10 became the first human-made object to cross the orbit of Pluto. At this point in time, Pluto was closer to the Sun than Neptune, as a portion of their orbits overlap. At this time, Pluto was still considered a planet and would be for 23 more years.
An artist’s impression of a Pioneer spacecraft on its way to interstellar space. Image credit: NASA Ames/Don Davis
