Scorpius, (Latin: “Scorpion”) also called Scorpio, in astronomy, zodiacal constellation lying in the southern sky between Libra and Sagittarius, at about 16 hours 30 minutes right ascension and 30° south declination. Its brightest star, Antares (Alpha Scorpii), the 15th brightest star in the sky, has a magnitude of 1.1. Its name comes from the Greek for “rival of Ares” (i.e., rival of the planet Mars) and was probably given because of the star’s red colour and brightness. The brightest X-ray source in the sky, Scorpius X-1, is found in this constellation. In astrology, Scorpius (or Scorpio) is the eighth sign