Scorpius: The Celestial Scorpion

Scorpius is one of the most visually stunning constellations in the sky. Its curving line of bright stars genuinely resembles a scorpion, complete with claws, body, and a stinging tail. Hugging the southern horizon during summer evenings for northern observers, Scorpius contains the brilliant red supergiant Antares and some of the richest star fields in the Milky Way. Track its position live with StarGlobe.

How to Find Scorpius

From the Northern Hemisphere, look low in the south during summer evenings, from June through August. Antares, the scorpion's heart, is a distinctly reddish star that stands out against the brighter Milky Way background. Once you spot Antares, trace the line of stars curving to the left (east) and downward toward the horizon. This curving tail, ending in two close stars representing the stinger, is one of the most graceful shapes in the sky.

To the upper right of Antares, three stars in a vertical row form the scorpion's head. The claws originally extended further to the west, but the Romans separated them to create the constellation Libra.

From the Southern Hemisphere, Scorpius is magnificent. It rises high in the sky, and its full tail arc is easily visible. Southern observers enjoy a much more complete view of this constellation than those in northern latitudes, where the tail barely clears the horizon.

The Stars of Scorpius

Antares, whose name means "rival of Mars" for its reddish hue, is a red supergiant roughly 550 light-years away. It is one of the largest stars visible to the unaided eye, with a diameter that would extend past the orbit of Mars if placed at the center of our solar system. Antares is a semi-regular variable star that fluctuates between about magnitude 0.6 and 1.6.

Shaula and Lesath mark the scorpion's stinger at the tip of the tail. Shaula, at magnitude 1.6, is actually the second-brightest star in the constellation. Together, these two stars are sometimes called the Cat's Eyes because of their close pairing.

Dschubba marks the central star of the scorpion's head. It is a hot blue-white star that has undergone sudden brightness increases, most notably in 2000 when it brightened by half a magnitude due to the ejection of a gas shell. The head stars collectively form a distinctive vertical line that is easy to identify.

Star Clusters and Deep Sky Objects

Scorpius is extraordinarily rich in deep sky objects because it lies along one of the densest parts of the Milky Way, looking toward the galactic center. M7, the Ptolemy Cluster, is a large and bright open cluster near the stinger, visible to the naked eye as a hazy patch. Ptolemy recorded it in the second century, making it one of the earliest cataloged deep sky objects.

M6, the Butterfly Cluster, sits just north of M7 and gets its name from the wing-like pattern of its brighter stars. Both clusters are spectacular in binoculars. M4, located just west of Antares, is one of the nearest globular clusters to Earth at about 7,200 light-years. It is one of the easiest globulars to resolve into individual stars with a modest telescope.

M80 is another globular cluster in Scorpius, notable for being extremely dense at its center. The open cluster NGC 6231, embedded in a region of bright nebulosity near the base of the tail, is sometimes called the Northern Jewel Box for its brilliant collection of hot blue stars.

Mythology and Cultural Significance

The most famous myth associated with Scorpius involves Orion. When the hunter Orion boasted that he could kill every animal on Earth, the goddess Gaia (or in some versions Artemis) sent a giant scorpion to stop him. The scorpion succeeded, and both were placed in the sky on opposite sides so they would never be above the horizon at the same time. Indeed, as Scorpius rises in the southeast on summer evenings, Orion is setting in the west.

In Polynesian navigation traditions, the curved tail of Scorpius served as an important directional marker. The Maori of New Zealand knew the constellation as Te Matau a Maui, the fishhook of the demigod Maui, which he used to pull the North Island of New Zealand from the sea. In Chinese astronomy, the heart of Scorpius was one of the four Royal Stars marking the cardinal directions.

Best Time to Observe

Scorpius is best observed during June, July, and August for Northern Hemisphere observers, when it crosses the meridian during evening hours. Because it lies far south on the ecliptic, the constellation never rises very high from northern latitudes above about 40 degrees, and the tail may be partially hidden by the horizon. Choose a location with a clear southern horizon for the best view.

Southern Hemisphere observers enjoy Scorpius during their winter months (June through August), when it passes high overhead and its full glory, including the rich star clouds of the Milky Way behind it, is on full display.

Neighboring Constellations

Sagittarius lies to the east, toward the galactic center. Libra, originally the scorpion's claws, sits to the west. Lupus is below and to the west, while Ophiuchus, the serpent bearer, encroaches from the north, actually separating a small portion of the ecliptic between Scorpius and Sagittarius. Corona Australis lies to the southeast.

The summer Milky Way stretching from Scorpius through Sagittarius is one of the most impressive sights in the night sky, visible from dark locations as a glowing band of light dense with stars, clusters, and nebulae. Open StarGlobe to explore this spectacular region.

Quick Facts

Scorpius covers 497 square degrees, ranking 33rd in size. It contains four Messier objects and numerous bright star clusters. Antares shines at an average magnitude of about 1.1, and the constellation has over a dozen stars brighter than magnitude 3.5. Its right ascension ranges from about 15h 47m to 17h 50m, and its declination spans from about -8 to -46 degrees.