This week brings the largest supermoon of the year. Supermoons occur because the moon’s orbit is not perfectly circular around the Earth. Instead, it is an ellipse, meaning that sometimes the moon will be closer to the Earth than at other times.
When a full moon coincides with the moon being within 10% of its closest point to Earth, we call it a supermoon. Its proximity makes it appear subtly bigger and brighter than other full moons.
On 5 November 2025, the moon will be just under 357,000km from Earth, making it the nearest full moon of the year, and therefore the largest supermoon. It will appear 8% larger and about 16% brighter than average.
It is a dramatic sight to watch the bright limb of the moon peep above the horizon as the twilight gathers around it. It will rise in the east around sunset, about 15:52 GMT for London. The drama is partly due to something called the moon illusion, which makes the moon appear larger when it is close to the horizon and we have other objects to gauge it against. As the moon rises higher, our brains start telling us that it looks smaller but in reality nothing has changed.
