Lunar illusion! Why does Moon look bigger on some nights?

Have you ever looked up to the night sky to watch the Moon and the stars, and wondered if the Moon looked bigger than usual? If yes, then you’re not alone in this. Moon does actually appear bigger on some nights. Why? We’ve got this lunar illusion business covered for you. So, read on to find out.

The Moon appears bigger and closer to Earth on some nights compared to others due to an illusion in our minds. (AFP)

Have you ever looked up to the night sky to watch the Moon and the stars, and wondered if the Moon looked bigger than usual? If yes, then you're not alone in this. Moon does actually appear bigger and closer on some nights. Here's why.

The Moon creates an illusion which makes us think its bigger and closer to the Earth on some nights whereas it seems farther away on other nights. This illusion has been the topic of discussion for astronomers for centuries. The Moon has always fascinated astronomers, sky watchers as well as story-tellers for its mysterious nature.

Why Does it Happen?

According to The Conversation, the Moon looks bigger and closer when it is closer to the horizon. That is because the horizon provides a reference as to how big the Moon actually is. Our mind judges the size of objects by comparing it to other things familiar to it.

In simpler terms, the Moon is so far away from Earth that no matter what day or weather, it is EXACTLY the same size. So, when the Moon rises next to a familiar object like your house far away or a nearby hill, it appears bigger and closer.

Explanation Behind it

This phenomenon can actually be photographed and captured on camera. There are several explanations of this phenomenon, some scientists say the atmosphere works like a lens and magnifies the Moon's appearance on Earth. Refraction of light takes place where the Earth's atmosphere acts like a prism and bends the light in a certain way.

Another explanation is that the Moon actually IS closer to Earth on some nights. This happens due to the Moon not being in a perfect circular orbit, but an elliptical one which brings it near to the Earth on some nights.

You can try this experiment for yourself. Next time you see the Moon at night, cover the Moon with your finger. Then, when it rises further, try to cover it again with the same finger. If it fits, then the illusion has not taken place that night, and if it doesn't, then you've seen the Moon illusion for yourself!