Discovered by Charles Messier on March 20, 1781
M93 is a small open cluster consisting of at least 80 true members. Most of the brightest stars in the cluster are blue giants. The extent of the cluster is about two thirds of the full Moon's diameter. This makes it small in comparison to most open star clusters. The age of M93 is estimated to be approximately 100 million years, thus making it a "middle-aged" cluster. The cluster is relatively bright at magnitude 6.0 and is easily observed in small telescopes. M93 is located in the constellation Puppis at a distance of approximately 3,600 light years from the Earth.