Milton La Salle Humason (August 19, 1891 – June 18, 1972) was an American astronomer.
He worked with Edwin Hubble to measure the redshift of nebulas in the early 20th century, providing evidence of the expansion of the universe.
Eleven years before Clyde Tombaugh, Humason took a set of four photographs in which the image of Pluto appeared.
[3] There is persistent speculation that he missed discovering the dwarf planet because it fell on a defect in the photographic plate.
In the popular documentary Cosmos: A Personal Voyage by astronomer Carl Sagan, Humason's life and work are portrayed on screen in episode 10: The Edge of Forever.