Libra, the Scales, is part of the zodiac, and in ancient times it was seen as the claws of a much larger Scorpius. Alpha Librae is a widely separated but pretty double star best viewed through binoculars or a small telescope at low power. Another easy and beautiful double star in this part of the sky is Beta Scorpii. The constellation Hercules is named for the legendary strongman of Greek myth. Its chief claim to fame is its grand globular star cluster, M13.
Globular clusters are spherical gatherings of tens to hundreds of thousands of stars.
M13, labeled on the map at right, can be glimpsed with the naked eye in clear, moonless country skies. Even in light-polluted suburbs, binoculars show it as a fuzzy little blob. In a telescope, however, it becomes an impressive, dimly glowing ball. Through 6-inch or larger instruments, it begins to sparkle with individual stars. Hercules is not the only constellation between Arcturus and Vega.