Clyde Tombaugh discovered Pluto in 1930 at Lowell Observatory in Flagstaff. Here's how Pluto won - and lost - its planetary ...

“New Horizons shattered a major paradigm of planetary science,” says Alan Stern, the mission’s principal investigator. “Pluto turns out to have as much complexity as Mars or Earth, so much so that I ...

Clyde Tombaugh didn't set out to discover Pluto when he sent his sketches of the night sky to Lowell Observatory in Flagstaff, Arizona in 1929. More than anything, he just wanted to get off the ...

Years after his death, Tombaugh used a blink comparator to analyze photographic plates of the night sky, eventually spotting Pluto. Today, visitors can explore Lowell Observatory, which opened an ...