Donald Edward Machholz, born October 7, 1952 in Portsmouth, Virginia, is an American amateur astronomer from Colfax, California.
He is the most successful living visual comet hunter in the United States, being credited with the discovery of 11 comets, including the periodic comets 96P/Machholz, 141P/Machholz, the non-periodic C/2004 Q2 (Machholz) that was easily visible in binoculars in the northern sky in 2004 and 2005, and most recently, C/2010 F4 (Machholz).[1][2]
Machholz is also considered to be one of the inventors of the Messier marathon, which is a race to observe all the Messier objects in a single night.