Ninety years ago Tuesday, a self-taught astronomer discovered what became known as the ninth planet in the solar system — Pluto. It happened at the Lowell Observatory in Flagstaff.
The observatory’s namesake saw evidence that a "Planet X" existed, but Percival Lowell died in 1916 before he could find it. Then, in 1930, a 24-year-old man with no college education, Clyde Tombaugh, identified a previously unknown planet by comparing photographs captured by the Lowell telescope. The discovery made international headlines.
“This really changed the solar system — what we knew about the solar system up to this point, the last planet was Neptune, this planet too the solar system out much further,” said Lowell Observatory historian Kevin Schindler.
Schindler says the discovery put Flagstaff on the map. But in 2006, the International Astronomical Union redefined the term "planet," relegating Pluto to a "dwarf planet," meaning it was no longer the ninth planet from the Sun.
The delisting was a blow to the Tombaugh family and the Lowell Observatory, but the importance of the discovery lives on.
"You know Pluto is the little planet that could against the big bullies of the solar system in all these ways that people kind of use Pluto as a symbol of overcoming unusual odds."
The Lowell Observatory will celebrate the 90th anniversary of Pluto’s discovery with the I Heart Pluto Festival tonight at the Orpheum Theater in Flagstaff. You can also find "Pluto" themed keepsakes and food in downtown Flagstaff.
By the way, Pluto got its name after a 11-year-old British girl suggested it to her grandfather, who passed it along to the Lowell Observatory. The first two letters in Pluto are the initials of Percival Lowell, who believed the planet existed.
And of course, Walt Disney named his sixth animated character — a dog — after the former planet.
