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. He was, in fact, the number one living visual comet discoverer. Eventually, he spent 8,900 hours comet hunting, during which he discovered a total of 12 comets which bear his name. Subsequently, his second find took an additional 1,742 hours. He found his first comet on September 12, 1978, after 1,700 hours of searching. Consequently, he decided to attempt a comet hunting program, which he began on January 1, 1975. Later, he received a 6-inch (15-cm) Criterion Dynascope and found all the Messier Objects in one year (1969-70).

With this in mind, he received his first telescope on October 7, 1965, a 2-inch (5-cm) refractor. Don Machholz: comet hunterĭon became interested in astronomy at age 8. We send our condolences to his wife, Michele, and to his two sons. Indeed, he had a great love of the night sky and shared his boundless knowledge with our readers, using his characteristic wit. Don was a friend and colleague at EarthSky. We are heartbroken to announce the passing of Don Machholz on August 9, 2022, at his home – Stargazer Ranch, Arizona – under one of the darkest skies in North America. And he was a writer for EarthSky … and our friend. He was one of the inventors of the Messier marathon, which amateur astronomers around the world use to test their skill.

Don Machholz visually discovered 12 comets that bear his name.

1965 comet