Star
Antares
Antares is the red supergiant at the heart of Scorpius the scorpion. Its name means the rival of Mars, and in 2026 it sits at 10 degrees of the sign Sagittarius.
Where the name comes from
Antares comes from the Greek for the rival of Mars, or against Mars. It shines the same ruddy red as the planet, and because Mars regularly drifts through this part of the sky, the two can sit side by side looking almost identical. The name is really an ancient note of caution, telling you which red dot is the star.
A heart big enough to swallow Mars
Antares marks the heart of Scorpius, and it is a red supergiant of staggering size. Dropped into our solar system it would reach out past the orbit of Mars. Like Betelgeuse, it is near the end of its life and will one day end as a supernova. It also has a small, hot blue companion star, which is hard to see in its glare but shows up in a good telescope on a steady night.
How to find it
Antares is the bright red star at the centre of the curved line of Scorpius, low in the south on summer evenings from mid northern latitudes and high overhead from the southern hemisphere. Three stars in a short arc above it mark the scorpion’s head and claws, and the long tail curls away below. The catalogue Hali uses puts its brightness at about magnitude 1.
When the Moon covers it
Antares lies close to the ecliptic, so the Moon passes very near it every month. In some years the Moon slides directly in front of it, an occultation, and the red star blinks out in an instant, because stars are so far away that they are points, with no width to fade across. It is one of only four first magnitude stars the Moon can ever cover, along with Aldebaran, Regulus and Spica.
Antares in a chart
By Hali’s 2026 star positions Antares sits at 10 degrees of the sign Sagittarius, and the Sun reaches that degree around 2 December each year. Ptolemy gave the bright star at the scorpion’s heart the nature of Mars with a little Jupiter, and it is one of the fifteen Behenian stars of medieval astrology. Astrologers who use fixed stars read a planet or angle close to it as intensity, courage and a fighting streak, with a warning about recklessness.
Common confusions
Antares is not in the sign Scorpio, though it is the heart of the constellation Scorpius. Precession has carried it into the sign Sagittarius. And when a red point sits near Scorpius it may be Mars rather than Antares. If it shines without twinkling and moves over a few nights, it is the planet.
Questions
Why is Antares called the rival of Mars?
Because it glows the same deep red as the planet Mars, and the two are often mistaken for each other when Mars passes nearby. The name is a warning not to confuse them.
Can you see Antares from northern Europe?
Only from the south of it, and low. By Hali's star positions Antares never rises anywhere north of about 63.6 degrees north, so Reykjavík never sees it at all, and from London it climbs only a little way above the southern horizon on summer nights.
Sources: Standard stellar references. Hali star positions for 2026, from Yale Bright Star Catalogue coordinates.