How to Use Hercules 'Keystone' to Find ‘Million Star’ Cluster | June 2014 Skywatching Video

A lopsided square of 4 stars called the 'Keystone', found in he Hercules Constellation, points the way to the Hercules Cluster (M31). Draco (the Dragon) and Boötes (the Herdsman) also highlight June's skywatching. (Skywatching Guide)

credit : Space Telescope Science Institute, Office of Public Outreach