Slipher, Vesto Melvin

BornNear Mulberry, Indiana, USA, 11 November 1875

DiedFlagstaff, Arizona, USA, 8 November 1969

American spectroscopist Vesto Slipher is now remembered primarily as the person who obtained the spectra and measured the first radial velocities of the spiral nebulae showing that most were receding from the Earth. Milton Humason extended Slipher’s measurements to more and more distant galaxies; this led to Edwin Hubble ’s discovery of the velocity-distance relation and, therefore, the expansion of the universe.

Slipher was the son of David Clark and Hannah App Slipher; his brother, Earl Slipher , also was an astronomer who also spent most of his career at Lowell Observatory, being associated primarily with photography of the giant planets and their satellites. Vesto received his degrees from the University of Indiana (A.B., 1901; A.M., 1903; Ph.D., 1909; honorary Ph.D., 1929) and honorary degrees also from the University of Arizona, University of Toronto, and Arizona State University....