As darkness falls in August, the Summer Triangle, made up of three bright stars from three different constellations, is the first shape visible in the celestial sphere. Full darkness brings the full glory of the Milky Way, arching across the sky from the south to the northeast, passing right behind the Summer Triangle due overhead. Scan its glowing star clouds with binoculars or a telescope to see star clusters and nebulas by the dozens.
The Big Dipper, an asterism, or star shape, within the constellation Ursa Major, the Great Bear, is hanging low in the northwestern quadrant of the sky, its cup upright to hold water, as the saying goes. The arc of its handle points to Arcturus, the big orange alpha (or brightest) star in the constellation Bootes, the Herdsman. Vega, the constellation Lyra's bright blue-white alpha star, is now almost directly overhead. It marks one corner of the Summer Triangle. High in the northeastern part of the sky is another corner, Deneb, the alpha star in Cygnus, the Swan. Deneb marks the swan's tail; locate the head and wings and you will see why this constellation is sometimes called the Northern Cross.
Below Cygnus is the huge Great Square of Pegasus, the Winged Horse. Running from the lower left corner of the Great Square are two lines of stars forming Andromeda, the Princess. On a very dark, clear night you might be able to make out a fuzzy patch of light above the middle of these lines; this is the Great Andromeda Galaxy, the most distant object the eye (unaided by binoculars or a telescope) can see. Just rising low in the northeast are the stars of Perseus, the Hero, who in legend rescued Andromeda from Cetus, the Sea Monster.
Altair, the alpha star in the constellation Aquila, the Eagle, is midway up in the southeastern portion of the sky. It marks the third corner of the Summer Triangle. Below Aquila are the faint stars making up the roughly triangular Capricornus, the Sea Goat. Above these stars are farther to the left, toward the east, are the stars of Aquarius, the Waterbearer.
The intriguing constellation Scorpius, the Scorpion, and its bright red alpha star, Antares, are low in the southwest. If the sky is really dark, now is a good time to find the huge figure of Ophiuchus, the Serpent Bearer, and the two parts of Serpens, the Serpent, that entwine it. These faint stars occupy a large part of the southwestern sky above Scorpius. Above and to the right of Ophiuchus is Hercules, the Strongman. Right above the southern horizon is Sagittarius, the Archer, now as high as it ever gets in northern latitudes. Like Scorpius, this is a wonderful constellation to study with binoculars or a telescope. Both lie in the direction of the center of our galaxy, and the star clouds and nebulas are thickest here. Be sure to trace the Teapot asterism in the stars of Sagittarius.