If you’ve glanced at a full moon over the last few months, the chances are you saw a supermoon.

That’s because we’ve had three in as many months. And, on Thursday, we’ll be treated to the fourth — and last — supermoon of the year.

With skies across much of the country expected to be clear, it should be a great opportunity to spot a full moon that may appear larger and brighter than normal.

‘Supermoons’ take place when a full moon coincides — or comes close to coinciding — with the moon’s ‘perigee’: the point in its orbit where it’s closest to Earth.

The moon’s orbit is elliptical, swinging between 253,000 and 226,000 miles away from our planet over a month. On Thursday, it will be around 223,600 miles from the Earth’s centre when it passes the meridian.

Astronomers would call full moons that take place on or around the closest point of orbit ‘perigeal’, or even an example of ‘perigee syzygy.’ But these terms aren’t quite as catchy as 1970s-coined ‘supermoon’.

Realistically, it won’t look that much bigger to human eyes than it will during any other month.

The full moon itself won’t start until 2:35am Friday morning. At this point it will be high in the sky and won’t realistically look all that much bigger to human eyes than it would during any other month.

But if you look for the moon soon after its risen, you may benefit from an illusion that sometimes makes our natural satellite look bigger.

No-one is exactly sure what causes this ‘moon illusion’, as space historian Osnat Katz writes in The Conversation, but it really is just something our minds create.

You can tell because you’ll be able to block it out in the sky with just your thumb, however big it appears.

Some scientists think the illusion might occur because the moon is nearer the horizon at this point. This may trick our brains into thinking it’s closer than it is.

Whatever the reason, it’s an illusion that’s been documented for thousands of years.

On Thursday, the moon will rise at 8.54pm in London, before setting at 5.34am the next day. In Edinburgh, it will rise around 9.30pm and set at 5.25am Friday, according to timeanddate.com.

August’s full moon is often known as the ‘Sturgeon moon’ because it took place around the time Native Americans in some regions would historically catch very large numbers of the fish, according to the Old Farmer’s Almanac.

Source: Read Full Article