One think you'll hear about a lot these days is the amazing Super Moon. In the last few years particularly, the popular media seem to have latched on to this amazing astronomical spectacle, and made it their mission to let us know about every upcoming Super Moon, and to tell us to be sure to go outside and marvel at the sight.

While I'm obviously glad to see the mainstream media encourage an interest in astronomical events, the problem here is that they have got it completely wrong. As an astronomical spectacle, the Super Moon simply doesn't exist — it is essentially a hoax which journalists use to fill space and get clicks. Which is tragic, because there are plenty of real astronomical things going on which they could, and should, be telling you about.

The Super Moon Hoax

The Super Moon, promoted as a spectacular phenomenon by the mainstream media, is a hoax. But, like many hoaxes, it's based on a grain of truth.

The truth here is that the Moon does, in fact, change size. Of course, it doesn't really grow and shrink, but because its orbit is elliptical, its distance from the Earth changes, and this makes its apparent size in the sky change. So, there will be times when it is larger than average; and sometimes this will coincide with a full Moon. This is what the media calls a Super Moon.

The problem is the amount of change which we can see. While the media use phrases like "amazing supermoon", and "one of the most spectacular sights you could ever hope to see", the reality is that there's almost no way you could see this in real life.

Of course many people have seen the Moon looking huge, much larger than average — like 50% larger than normal. This will happen when the Moon is close to the horizon; what you're seeing is actually the Moon Illusion. This is purely an optical illusion, and it happens with any state of the Moon, regardless of whether it's "Super" or not.

On the Statistics page you will find information on the Sizes of the Sun and Moon; and the Moon Data page displays detailed information on the Moon's key dates. To summarise, the Moon's apparent size when directly overhead varies from 0.497° to 0.569°, with an average around 0.530° (apparent sizes are measured as angles). This means that at largest, the Moon is about 7.2% larger than average. And 7.2% is just paltry. Calling this "Super" is absurd.

So yes, it's true that a full Moon can be larger than average; the problem is that there's almost no way that you could see this with the naked eye. The picture here shows the difference between an average Moon and a "Super Moon":


A full moon and "super moon". Spot the difference.

Seeing these side-by-side on your screen, you can probably see the difference quite easily — particularly when you look at the size of the black borders around the two Moons. But if you imagine seeing these separately, a month apart, it should be clear that the difference is just too small to observe without measurement.

If you want to known when the next "super" Moon is happening, you can find it with our Moon Calendar. Just look for a date when the full Moon coincides with perigee.

Media Shame

Here are some typical examples of the media's supermoon rubbish:

If you go outside at night on 13/14 November, you might get to enjoy something quite spectacular. You will see an amazing supermoon up in the night sky, which means the Moon will be very big and bright.
BBC Newsround: How to see biggest supermoon in almost 70 yearsHow to see biggest supermoon in almost 70 years
A dreadful BBC supermoon article. (BBC Newsround)
http://www.bbc.co.uk/newsround/37860505

This is just false — no, you won't see an amazing supermoon, and the Moon won't be very big and bright; or at least not noticeably more so than usual. The Moon Illusion complicates this, but you can see that any time there's a full Moon.

HAVE you ever seen a supermoon? If not you are missing out on one of the most spectacular sights you could ever hope to see.
The Sun: When is the next supermoon in the UK?When is the next supermoon in the UK?
A poor (unsurprisingly) supermoon article from The Sun. (The Sun)
https://www.thesun.co.uk/tech/2382383/supermoon-when-next-2018-dates-2018/

Wrong; it looks just like any other full Moon.

Supermoons are a rare type of full moon. They appear up to 14% bigger and 30% brighter than normal. While the full moon rises about once per month, supermoons can only occur a few times per year — max.
Business Insider: What is a supermoon?What is a supermoon?
A bad supermoon article from Business Insider. (Business Insider)
http://uk.businessinsider.com/what-is-a-supermoon-2017-11

Wrong again: the "super" Moon is 7% bigger than average, not the 14% clearly implied here. Also the statement that "supermoons can only occur a few times per year — max" is just strange; given that there are only 12 or 13 full Moons in a year, saying that "a few" of them are supermoons implies a high frequency of supermoons.

Sometimes the BBC, despite their breathless enthusiasm, make a genuine effort to get the facts straight:

To observers, the Moon appears about 7% larger and 15% brighter, although the difference is barely noticeable to the human eye.
BBC News: 'Supermoon' brightens up skies for stargazers'Supermoon' brightens up skies for stargazers
A slightly better BBC supermoon article. (BBC News)
https://www.bbc.co.uk/news/uk-42211288

This is actually correct; although it contradicts the whole tone of the article, and indeed the point of the article even existing. It also directly contradicts the opening statement "... when the Moon appears larger and brighter in the sky".

The Moon Illusion

The Moon Illusion is a very well-known and much-studied optical illusion which causes the Moon (whether full or not) to appear enormously large when it is close to the horizon. The Moon Illusion has nothing to do with the actual size of the Moon in the sky; it is purely an optical illusion.

The problem is that when people hear about a supermoon, they will tend to go out and look at the Moon — usually right after it rises, when it is close to the horizon. The Moon Illusion then makes it look huge, which reinforces the idea that the supermoon is real. In reality, though, this is easily debunked:

Proving It

The Moon Illusion is very convincing, and really quite spectacular — the Moon looks massively bloated, and dominates the landscape. However, it is purely an optical illusion. You can prove this quite easily, any time the Moon is reasonably close to full:

One tip for photographing the full Moon — a normal digital camera will usually try to over-expose a Moon photo by a long way, as it tries to compensate for the mostly black sky. To get a well-exposed picture, try dialling the exposure down quite a lot.

This experiment proves that the apparent huge size of the Moon when it was low is purely caused by the way your brain interprets the scene. If it was caused by atmospheric refraction, or some such external thing, then the camera would have seen and recorded the same effect.

Wikipedia's articleMoon illusion
An article on the Moon Illusion, which makes the Moon appear very large when close to the horizon. (Wikipedia)
https://en.wikipedia.org/wiki/Moon_illusion on the Moon Illusion describes it in more detail.

Genuine Sky Spectacles

As we said in the introduction, it's tragic that the media are putting such effort into peddling garbage like the "Super Moon" when they could be telling you about all kinds of real astronomical phenomena that you could easily be observing. So, like what? Well, an eclipse, obviously! But in between eclipses, there are plenty of other things to see in the sky. Here are some ideas.

The Moon!


The half Moon, about a week before Full Moon.

The Moon is awesome! Yes, certainly go out and look at it when it's full — don't wait for the media to be blathering about super moons. Use binoculars, take pictures, go wild! A picture of the full Moon rising beside some Earthly scene, like trees or buildings, could be amazing — but bear in mind that if you want it to look as big in a picture as it does to your eye, you will need a very long telephoto lens.

Better than the full Moon, though, is the half Moon — specially through binoculars or a telescope. About a week before the full Moon, go outside on a clear night; after sunset, the half Moon should be high in the sky. With the sunlight slanting across the lunar surface — as opposed to shining straight down on it — the surface features are thrown into amazing and spectacular relief. Check it out for yourself!

Jupiter

Another one for binoculars — check it out when the planet is reasonably high above the horizon after dark. Take a good look and you should see up to four sharp points of light near it — those are Moons of Jupiter. In fact they're the Galilean Moons, which Galileo used to show that the Earth isn't the centre of everything.

Meteor Showers

Meteor showers can be spectacular events to see, though be prepared to hang out after midnight, and have a bit of patience. There are plenty of online guides to the 11 major meteor showers in a year, so there are lots of opportunities to see this beautiful spectacle.

Sunspots

This one involves looking at the Sun, so eye safety is paramount; using a solar projector is probably the best way to go. With this set up, you should be able to see sunspots quite easily, at times of significant solar activity.

Unfortunately, at the time of writing (2018) the Sun seems to be entering a particularly quiet phase. However, there are still occasional sunspots, and even at the quietest time there can be large areas of solar activity. And of course the quiet period won't last forever. So set up your projector!

And More!

There are so many astronomical events that can easily be seen by amateurs that there's no way to list them all here. However, a quick search for back yard astronomy, or binocular astronomy, will turn up many, many inspirational ideas, and sources of information.