Ellen Susanna Howell (born 1961;[1] also published as Ellen S. Bus) is an American astronomer and planetary scientist who studies the composition and structure of asteroids and comets within the Solar System.
She is a research professor at the Lunar and Planetary Laboratory of the University of Arizona, and a team member for the OSIRIS-REx sample-and-return space mission.
[2] Howell majored in geophysics at the California Institute of Technology, graduating in 1981.
Returning to graduate study, she completed a Ph.D. in planetary sciences at the University of Arizona in 1995.
[3] In 1977, Howell discovered asteroid 3598 Saucier using the Palomar Observatory.