Clyde W. Tombaugh's Photographic Plates

Origin
In 1930, using the calculations of Percival Lowell and W.H. Pickering, Tombaugh discovered the ninth planet in the solar system, Pluto. It was verified by several other scientists before being officially announced the following month. Tombaugh discovered the planet's location by using photographic plates and a blink telescope at the Lowell Observatory.

Effects
Holding a plate up to the night sky copies that area of the sky onto the plate and allows the user to see changes in the night sky by solar system objects allowing the user to identify them.