Flexi Says: Clyde Tombaugh discovered Pluto in 1930. He used the telescope with a camera that clicks two photographs of the sky on different days. The photographs were flipped back and forth using a blink compactor. Tombaugh spent around a week studying each pair of photographs with over a million stars. While studying the photographs for days, he observed the movement of an object across the field of a pair of images. After studying the object, he determined it to be a planet in our solar system.
