Find Hercules’s four-star Keystone between Vega and Arcturus. M13 lies along its western side, between Eta and Zeta Herculis, closer to Eta. In binoculars, expect a fuzzy point rather than the resolved swarm in this photograph.

It ranks tenth: a worthwhile globular-cluster challenge, but less immediately rewarding than Mizar and Alcor. Choose a dark, clear night and confirm the field with a map before deciding that every blurred point is a cluster.

Sources: NASA Night Sky Network.

Image: Thedarksideobservatory · CC BY-SA 4.0. Resized and JPEG compressed; original license retained.