A FULL Moon will rise tonight – and our brains are about to be tricked by the lesser known "moon illusion".

Scientists say that when you see the moon looking really large as it rises in the sky your brain is actually playing a trick on you.

On the night of August 15, you should be able to spot a full moon in the sky.

It is known as the Sturgeon Moon because it is around this time of year that lots of sturgeon fish are caught.

The Sturgeon Moon is going to seem very big as it rises in the sky but, in reality it will be the exact same size when it appears on the horizon as it will be when it's high in the sky.

There are many theories surrounding why this is but the main theory is that when the moon is low on the horizon it can be compared to many earthly things, like buildings and trees, and this is why it seems huge.

However, in comparison to the vast sky it will seem small because there is nothing to compare it to.

This is similar to an effect known as the Ebbinghaus Illusion, which shows how objects of the same size can look bigger or smaller depending on what they are surrounded by.

According to the moon illusion theory, if you bend over and look through your legs at the full moon rising, it won't seem as big because the objects surrounding it will no longer register as familiar because you're upside down.

Low moons often also appear red or orange in colour because when a large full moon is seen low in the sky it is being viewed through a greater thickness of the Earth's atmosphere.

Earth's oxygen and nitrogen-rich atmosphere filters out the bluer wavelengths of white moonlight when the moon is close to the horizon as it rises.

This filtering process, known as light refraction, results in more of the red component of moonlight travelling directly into your eye.

Therefore the Moon will appear red or orange to you.

The Moon can only really appear to have turned pink during a total lunar eclipses, which is often referred to as a a Blood Moon.