About the only good thing about the clocks going back is that the dark evenings reveal the Moon in all its glory, as long as the skies are clear enough. This Monday a full moon, called the Hunter’s Moon, loomed up like a great big glowing ball as it rose above the horizon.

In fact, it appeared unusually large thanks to a trick of the eye called the Moon Illusion. Psychologists say it is because the brain becomes confused as it calculates distances of objects on the horizon, such as trees or buildings, but cannot make sense of anything much farther away, such as the Moon, and overcompensates by making it larger. But if you look at the Moon through a cardboard tube the illusion disappears because you can no longer see the horizon and the Moon seems smaller.

The low-hanging Moon this week also appeared to be slightly pink or orange. Dust, smoke and pollution in the atmosphere scatter the moonlight and make it coloured, just as the Sun turns orange and red as it sets.

Much rarer was a lunar rainbow caught by the photographer Chris Walker, in Richmond, North Yorkshire (Times Online, Nov 4). Only at or about full Moon is moonlight bright enough to create a rainbow. In the same way that sunlight makes a normal rainbow, the moonlight is bent by raindrops, splits up into the colours of the spectrum and is reflected into a bow.