
Monday 6th to Sunday 12th October 2025
If you pop outside just as it's getting dark on the evening of Tuesday 7th, say around
A Full Moon reflects so much sunlight that it creates the ultimate natural light pollution and this will spoil your view of Saturn a bit. It is also the worst possible time to go hunting for faint deep sky targets.
We have just passed the autumn equinox and as this Full Moon is the closest to that date, it is known as the 2025 Harvest Moon. Coincidentally, this particular Full Moon occurs at perigee, when our celestial neighbour is closest to us in its orbit around the Earth.
In astronomy, there is no such thing as a perfect circle and all objects' orbits are elliptical (or egg-shaped) to a greater or lesser degree. In the case of our Moon, at perigee our natural satellite is approximately 225,000 miles away from us, where at the opposite point in its orbit, known as apogee, it is more like 251,000 miles away. This cycle repeats every 27 days, which is how long the Moon takes to go around us.
The Moon appears slightly larger when it is at perigee and the difference is size between the two extremes is about 14%. If a Full Moon occurs at perigee, it is known as a Supermoon. So on 7th, we really have a Harvest Supermoon!
Because the Moon will be close to the horizon when you view it, you may also witness that phenomenon known as "Moon Illusion" where your eyes play a trick on you and make it appear artificially large.
www.starsoversomerset.com
Screenshots courtesy of Stellarium
Moon images and diagrams courtesy of NASA
Copyright Adrian Dening and Radio Ninesprings 2025