Celebrate Pluto's 89th Anniversary of Discovery

Written by M.V. Moorhead Category: Culture Issue: February 2019
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Happy Birthday Pluto!

Well, OK, it's not exactly Pluto's birthday. Besides, if planets can be said to have birthdays, no doubt Pluto has had too many to make mentioning it polite. It's also controversial as to whether Pluto can even be called a planet, some years lowellobservatory2ago it was demoted to "dwarf planet"; now some astronomers are calling for its reinstatement to full planetary status.

But February 18th really is the 89th anniversary of Pluto's discovery by earthlings. Proud Arizonans know that the 9th Rock from the Sun was first spotted here on the 3rd Rock by astronomer Clyde Tombaugh in 1930 right here in our state, a short drive uphill from the Valley at Lowell Observatory in Flagstaff. The place is ground zero for human Pluto awareness.

If you want to learn more about our state's biggest claim to astronomical fame, or about the Universe in general, Lowell Observatory can make a fun road trip. Founded in 1894 by Percival Lowell, its initial focus of study was the planet Mars, which Lowell believed might be inhabited; he created striking maps of the Red Planet's supposed "canals." He died in 1916--his observatory-shaped mausoleum is on the Observatory grounds--but not before postulating the existence of a "Planet X" in the solar system beyond Neptune.

A decade and a half after Lowell's death, Tombaugh proved him right, and the sphere he spotted in the Kuiper Belt was named after the Roman god of the underworld. Mickey Mouse's dog, by the way, was named the following year; some historians believe that the little planet was the inspiration for this celebrated canine's moniker.


Daily activities at the Observatory include guided tours and peeks through the telescopes (weather permitting); there's also a fascinating collection of historical artifacts at the Rotunda Museum, and various lectures are offered. There's a cool outdoor walkway representing the distances between the Solar System's planets, to scale. Also cool: Because stargazing is best done at night, Lowell Observatory is open until 10 p.m. Monday through Saturday (until 5 p.m. Sunday). And, needless to say, there's a fine gift shop.

Lowell Observatory is located at 1400 West Mars Hill Road in Flagstaff. Admission is $17 for adults ($12 on Sunday); $16 for seniors, AAA, military and college students ($11 on Sunday); $10 for kids age 5-17 ($6 on Sunday) and free for kids younger than 5, and for members. Go to or call 928-774-3358 for details.