M11 has been described as one of the richest and most compact open clusters. This cluster lies 6,000 light years from Earth and has a diameter of about 21 light years. It is composed of more than 2,900 stars, 600 of which have a visual magnitude brighter than 15. To some, the shape of the cluster resembles that of a flock of flying ducks. This has helped it to earn the name, Wild Duck Cluster.