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Donald Machholz

From Wikipedia, the free encyclopedia
Donald Edward Machholz
Donald Machholz.JPG

Machholz examines his 18″ reflector telescope
Born Donald Edward Machholz
October 7, 1952 (age 64)
Portsmouth, Virginia
Nationality American
Fields Astronomy
Known for Comet discoveries
Spouse Michele Machholz

Donald Edward Machholz, born October 7, 1952, in Portsmouth, Virginia, is an American amateur astronomer who is the most successful living visual comet discoverer in the world. Credited with the discovery of 11 comets, that include the periodic comets 96P/Machholz, 141P/Machholz, the non-periodic C/2004 Q2 (Machholz) that were visible with binoculars in the northern sky in 2004 and 2005, and most recently, C/2010 F4 (Machholz).[1][2] In 1985, comet Machholz 1985-e, was discovered using a homemade cardboard telescope with a wide aperture, 10 inches across, that gave it a broader field of view than most commercial telescopes.[3] Amateur astronomer Machholz utilizes a variety of methods in his comet discoveries, in 1986 using 29×130 binoculars he discovered 96P/Machholz.[4]

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.



  • The Observing Guide to the Messier Marathon: A Handbook and Atlas
  • Decade of Comets: A Study of the 33 Comets Discovered by Amateur Astronomers Between 1975 and 1984
  • An observer’s guide to comet Hale-Bopp: Making the most of Comet Hale-Bopp: when and where to observe Comet Hale-Bopp and what to look for


  1. Gus Thomson (March 30, 2010). “Patience leads to new comet discovery by Colfax amateur astronomer”. Auburn Journal. Retrieved March 30, 2010.
  2. Roger W. Sinnott (March 27, 2010). “New Comet Machholz”. Sky & Telescope. Retrieved March 30, 2010.
  3. Associated Press (June 16, 1985). Amateur Astronomer Nails Down His Second Comet”. Los Angeles Times. Retrieved December 29, 2016.
  4. Alan MacRobert (December 2, 2008). “A Very Oddball Comet”. Sky & Telescope. Retrieved December 2, 2008.

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