The moon will be full on 26 May. This will coincide with the largest supermoon of the year, and also the first total lunar eclipse since January 2019. Although precise definitions vary, a supermoon is said to occur when the full moon takes place near the closest point in its orbit to the Earth. This week, the centre of the moon will be 357,462km away from the centre of the Earth. This is roughly 48,000km closer than the furthest full moon of the year, which will occur in December 2021. Total lunar eclipses can take place only when the moon is full as they require the Earth to be directly in between the Sun and the moon. As the moon slips fully into the Earth’s shadow, it turns a glorious red colour. This makes for a beautiful if seemingly “supernatural” appearance. Unfortunately, this week’s event is not the most favourably placed eclipse. The total “red” phase will only be visible from the west coasts of the Americas, the east coasts of Asia, and the Pacific territories in between. The eclipse is not visible from Africa and Europe, although the full supermoon will be easily seen.