Antares: The Red Heart of Scorpius

Look south on a summer evening and you\'ll see it: a distinctly reddish-orange star glowing low in the sky, marking the heart of Scorpius, the Scorpion. That\'s Antares, one of the brightest and most visually striking stars visible from Earth.

Why Is Antares Red?

Antares is a red supergiant, a star nearing the end of its life. It has exhausted the hydrogen fuel in its core and expanded to an enormous size. If you placed Antares where our Sun is, its outer atmosphere would extend past the orbit of Mars. That expansion has cooled its surface to about 3,500 Kelvin (compared to the Sun\'s 5,800 K), giving it that deep reddish hue.

Its name comes from the ancient Greek "anti-Ares," meaning "rival of Mars", because its red color is so similar to the Red Planet that ancient observers sometimes confused the two when Mars passed through Scorpius.

How to Find Antares

Antares is easy to spot if you know when and where to look:

• When: Best from May through September in the Northern Hemisphere. It\'s visible in the south/southwest during summer evenings.
• Where: Look for the distinctive J-shaped or fishhook pattern of Scorpius. Antares sits at the top of the curve, marking the scorpion\'s heart.
• Brightness: At magnitude +1.06, it\'s the 15th brightest star in the night sky. Its red color makes it easy to identify.

The Future of Antares

Antares is living on borrowed time. Within the next million years or so, it will run out of fuel entirely and explode as a supernova. When it does, it will briefly outshine every other star in the night sky and be visible in broad daylight. The remnant will likely become a neutron star or possibly a black hole.

For now, though, it\'s one of the most beautiful and accessible objects in the summer sky. You don\'t need a telescope, binoculars, or any special equipment. Just step outside on a clear summer night, look south, and find the red heart of the scorpion.