Starwatch: red jewel of Antares meets silvery charm of the moon | Astronomy
We are now well into May, and the moon is full and heading for a conjunction with the beautiful red jewel of Antares.
From London, this is a really close conjunction – the chart shows the view looking south-east on 23 May 2024 at 22:00BST. The moon’s visible surface will be 99.5% illuminated, and will rise virtually coincident with Antares.
To enjoy the spectacle, find the lowest south-eastern horizon you can and watch as the moon rises. As the night progresses, the doublet will rise higher into the sky and the moon will gradually pull away from the star.
Antares is the brightest star in the constellation of Scorpius, the scorpion. A red giant star, its radius is more than 650 times the size of the sun’s. Its colour denotes a relatively low surface temperature, hovering at about 3,600K (3,327C).
It is about 550 light years from Earth, meaning that its light has taken 550 years to reach us, hence why we are seeing the star as it looked more than half a millennium ago.
The moon, on the other hand, is just 1.3 light seconds away, so we see it as it looked 1.3 seconds ago. The conjunction will be visible around the world.
