Last night, stargazers around the world were dazzled by an exceptionally rare blue supermoon.
But if you missed out on last night’s spectacular display, there is no need to panic – as this is just the first of four upcoming lunar events.
A supermoon like last night occurs when the moon reaches 90 per cent of its closest distance to Earth.
Luckily, these events tend to come in clusters so there will be one to watch each month from now until November.
So, if you fancy getting in on the skygazing action, here are the key dates to make sure you have blocked off in your calendar.
Last night the rare blue supermoon lit up the skies in a spectacular display, as seen here from Copenhagen. But if you missed out, experts say there are more opportunities to come
Since the moon’s orbit around the Earth isn’t exactly circular the distance between the two changes throughout the year.
Normally, the moon remains around 238,600 miles (384,000 km) but during a supermoon that distance is significantly reduced.
Dr Edward Bloomer, senior astronomy manager at the Royal Observatory Greenwich, told MailOnline: ‘Due to the changing Earth-Moon distance, the Moon can appear slightly larger or smaller from the point of view of an observer on the Earth.
‘Supermoon isn’t actually a precise astronomical term, but in common usage, it is when the full moon occurs when the Moon is within 90 per cent of its minimum distance or maximum size.’
During yesterday’s supermoon, the moon was 14,300 miles (23,000km) closer than normal, a difference equivalent to almost twice the diameter of the Earth.
That difference causes the moon to appear 30 per cent brighter and 14 per cent larger to an observer on Earth.
Last night, photographers all around the world took advantage of this rare opportunity to capture stunning photos of the moon.
During a supermoon, the moon appears up to 30 per cent brighter and 14 per cent larger to an observer on Earth. Pictured, yesterday’s supermoon in Copenhagen, Denmark
Since the moon’s orbit is elliptical its distance to Earth changes throughout the year. When the moon is within 90 per cent of its closest point, this is called a supermoon
| Name | Date and Time | Distance from Earth |
|---|---|---|
| Harvest Moon | September 17, 02:34 GMT | 222,131 miles (357,486) |
| Hunter’s Moon | October 17, 11:26 GMT | 222,055 miles (357.364 km) |
| Beaver Moon | November 15, 21:29 GMT | 224,853 miles (361,867 km) |
In many of these images from the Northern Hemisphere, the moon also appears to be glowing red due to smoke from North American wildfires in the upper atmosphere.
However, many keen stargazers in the UK were left disappointed as thick cloud cover made it impossible to see anything throughout the night.
Thankfully, there is no need to feel any astronomical FOMO.
Dr Bloomer explains that supermoons tend to come in clusters of three or four because the moon cycles through its phases in a much shorter time than it takes to shift its elliptical orbit.
The difference is subtle but observers on Earth are able to see the difference between the moon at its closest point, or perigee, and its most distant point, or apogee
‘The “90%” criteria often allows for us to get a few consecutive full moons which qualify as a supermoon before the elliptical nature of the orbit means that those full moons are too far away to count as supermoons,’ says Dr Bloomer.
‘And at the other extreme, you can get a cluster of “micromoons”, where the full moon is occurring when the Earth-Moon distance is close to its maximum.’
Firstly, yesterday’s supermoon will still be full for the next two days so with a better forecast over England and Wales this evening there is still time to see the blue supermoon.
Then, each of the next three full moons will be within 90 per cent of the moon’s closest distance to Earth, also called its perigee, meaning they all count as supermoons.
Last night’s moon also appeared red or orange for many in the Northern Hemisphere due to the buildup of wildfire smoke in the atmosphere. Pictured, the supermoon above Boston, Massachusetts
If you want to catch these spectacular events, the dates to add to your diary are September 17, October 17, and November 15.
The October supermoon will be the biggest of the year as the moon reaches a distance of just 222,055 miles (357,364 km) from Earth – the closest it will get all year.
However, it is September’s supermoon which promises to be one of the most spectacular.
Not only will the moon be exceptionally close at just 222,131 miles (357,364 km) from Earth, but the full moon will also coincide with a partial lunar eclipse.
An eclipse of the moon occurs when the Earth moves directly between the sun and the moon, casting its shadow over the entire lunar surface.
Experts say there will be three more supermoons this year in September, October, and November. Pictured, the supermoon over Ankara, Turkey
During a partial eclipse, the moon passes through the outer edges of Earth’s shadow in a region called a penumbra.
Small regions of the moon can also be darkened by the complete shadow of the Earth or umbra.
During the September 18 partial eclipse, the maximum will occur at 03:44 am BST during which just 3.5 per cent of the moon will be in the umbra.
Since this will only lead to partial darkening of the moon it can be hard to spot so be sure to give yourself plenty of time to find a good view.
Dr Bloomer says: ‘There are plenty of apps available to let you know about the time and direction to best look for the Moon, so essentially a bit of planning ahead will help enormously.
To get the best view try to catch the moon while it is low to the horizon like this image of the supermoon over Athens, Greece. Due to an effect called the Moon Illusion, this causes the moon to appear larger
‘Then, it’s a case of trying to find a nearby area which doesn’t suffer from obscured views – a nice flat horizon is great.’
Due to an effect called the ‘moon illusion’ the moon appears to be larger while it is close to the horizon.
By timing your viewing around the moonrise, you can make use of this phenomenon to get an even more spectacular view.
You don’t need any special equipment to see the supermoon since they are so large and bright but using binoculars or a small telescope can help pick out some of the moon’s features.
A lot of your success will depend on getting clear skies so be sure to check the weather forecast before you head out.
Since the moon will appear full for three days you can be careful to choose an evening when you have the best weather.
The phases of the moon
Like Earth, the Moon has a day side and a night side, which change as the Moon rotates.
The Sun always illuminates half of the Moon while the other half remains dark, but how much we are able to see of that illuminated half changes as the Moon travels through its orbit.
In the Northern Hemisphere, the phases of the moon are:
1. New Moon
This is the invisible phase of the Moon, with the illuminated side of the Moon facing the Sun and the night side facing Earth.
2. Waxing crescent
This silver sliver of a Moon occurs when the illuminated half of the Moon faces mostly away from Earth, with only a tiny portion visible to us from our planet.
3. First Quarter
The Moon is now a quarter of the way through its monthly journey and you see half of its illuminated side.
4. Waxing Gibbous
Now most of the Moon’s dayside has come into view, and the Moon appears brighter in the sky.
5. Full Moon
This is as close as we come to seeing the Sun’s illumination of the entire day side of the Moon.
6. Waning Gibbous
As the Moon begins its journey back toward the Sun, the opposite side of the Moon now reflects the Moon’s light.
7. Last Quarter
The Moon looks like it’s half illuminated from the perspective of Earth, but really you’re seeing half of the half of the Moon that’s illuminated by the Sun ― or a quarter.
8. Waning Crescent
The Moon is nearly back to the point in its orbit where its dayside directly faces the Sun, and all that we see from our perspective is a thin curve.
