/Diary of anniversaries

february 18: 
Pluto Day (since 1930)

On February 18, 1930, Pluto was discovered by astronomer Clyde Tombaugh at the Lowell Observatory in Arizona. Originally considered the ninth planet in our solar system, Pluto was later classified as a dwarf planet due to new findings about its size and orbit. Pluto was named after the Roman god of the underworld, partly because the first two letters of Pluto were the initials of astronomer and founder of the Lowell Observatory Percival Lowell.