📅 18 February 1930
Clyde Tombaugh found a moving point in the photographic plates he had been comparing.
📅 18 February 1930
By comparing images of the same star field, Tombaugh detected the movement of the object later named Pluto.
📅 18 February 1930
The discovery itself took place on 18 February; public announcement and naming came later.
📅 18 February 1930
The object initially joined the planetary list and was reclassified as a dwarf planet many decades afterward.
