The second full moon of the month occurs this week. The first took place on 1 August, but this second coming will grace the skies on 31 August.
Because it is the second full supermoon in the month, it is also called a blue moon – although definitions for blue moons vary. The above definition is known as a monthly blue moon but some prefer what is known as a seasonal blue moon. This is the third full moon in a season that contains four full moons – so the blue moon may not be the second of the month.
But whether you think the one on 31 August is a blue moon or not, it is definitely a supermoon, the largest of the four supermoons occurring this year. The moon will be 222,043 miles (357,344km) away from Earth, hence the full moon will appear larger than average, earning it the title of supermoon. The day before the full moon occurs, the almost full moon will join Saturn in the evening sky. The silvery moonlight will make a subtle contrast to Saturn’s ochre glow. The chart shows the view looking south-east from London at 22.30 BST on 30 August 2023. The conjunction is much higher in the sky when viewed from the southern hemisphere.
