He teaches as a professor of radiology and orthopaedic surgery at the University of Arizona College of Medicine.
In 1987, together with David Crawford, he founded the International Dark-Sky Association, which has grown to more than 10,000 members in 75 countries (as of 2007).
He is also a member of the Planetary Science Institute Board of Trustees and a past chairman of the Western Region of the Astronomical League.
Asteroid 6398 Timhunter, discovered by Carolyn Shoemaker at Palomar Observatory in 1991, was named in his honor.
[1] The official naming citation was published by the Minor Planet Center on 1 June 1996 (M.P.C.