... M7: Open Star Cluster in Scorpius . ... M7 is one of the most prominent open clusters of stars on the sky. The cluster, dominated by bright blue stars, can be seen with the naked eye in a dark sky in the tail of the constellation of the Scorpion (Scorpius). Milky Way Over the Bungle Bungles . ... Curiosity on the Move . ... Curiosity is still almost.. ... Perhaps the most famous star cluster on the sky, the Pleiades can be seen without binoculars from even the depths of a light-polluted city. ...