Starwatch: silver moonlight in contrast with blood red Antares

 

The moon at first quarter will pass Antares, the heart of the scorpion, a red giant with an explosive future

This week, the moon will coast past the blood-red northern summer star of Antares in the constellation of Scorpius, the scorpion. The chart shows the view looking south-south-west from London on 25 August at 21:00 BST. The moon and Antares will be low in the sky, but the white brilliance of the moon and the deep red of Antares will make a pleasing contrast to each other. The moon will be at its first quarter phase, with 51% of its surface illuminated. A week from now, it will be full moon.

Antares is the brightest star in Scorpius and the 15th brightest star in the sky. Often described as the heart of the scorpion, it is nearly 600 light years away from us, meaning that the light we currently see started its journey across space in the early 1400s, a few decades before the Renaissance began in Europe. It is a red supergiant star, that would engulf Mercury, Venus, Earth, Mars and most of the asteroid belt were it to replace the sun. At this gigantic size, it gives off around 2750 times more light than the sun, and is destined one day to explode as a supernova.