Don became interested in astronomy at age 8. He received first telescope on Oct. 7, 1965, a 2-inch (5cm) refractor. Later he received a 6-inch (15 cm) Criterion Dynascope and found all the Messier Objects in one year (1969-70).
He decided to attempt a comet hunting program, which he began on Jan. 1, 1975, and found his first comet on Sept. 12, 1978, after 1700 hours of searching. His second find took an additional 1742 hours. He has now spent 8900 hours comet hunting during which he has discovered a total of 12 comets which bear his name. Don is the number one living visual comet discoverer.
In 1978, Don was one of the independent inventors of the Messier Marathon, an attempt to find and view all 110 galaxies, clusters, and nebulae in one night. In the last 40 years he has completed over 50 Messier Marathons and has written two books on the subject.
From 1978 through 2000, Don wrote a monthly column called "Comet Comments" for astronomy club newsletters and interested individuals worldwide. Between 1988 and 2000, Don was the Comets Recorder for the Association of Lunar and Planetary Observers.
Don continues his visual comet hunting and Messier Marathons from Arizona, where he lives with his wife Michele.
Don has a weekly podcast: “Looking Up With Don”, found on most podcast platforms.
His website is donmachholz.com