Pluto: A timeline of 85 years of discovery

PLUTO IN THE SPOTLIGHT A drifting point of light in the constellation Gemini observed between January 23 and 29, 1930, betrayed Pluto's existence. Several observations in the last 85 years have given astronomers a little more information about Pluto, and the July 2015 flyby will offer the closest look yet at the solar system's far-flung satellite.

Lowell Observatory Archives

By Christopher Crockett

July 11, 2015 at 2:03 pm

Clyde Tombaugh began searching for a ninth planet in 1929 and stumbled upon Pluto the following year. In the decades since, our view of Pluto hasn’t changed much. All of that changes on July 14 when the New Horizons spacecraft, nearly 5 billion kilometers from home, slipped past Pluto and gave humankind its only look at this icy world (see “Rendezvous with Pluto,” SN: 6/27/15, p. 16). Below are several milestones leading up to the 2015 Pluto flyby.