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Guide to the September 28th Total Lunar Eclipse

Very soon now, the Internet is going to be groaning under the weight of information about a total eclipse of the Moon happening on the morning of September 28th. Most of this information will be utter rubbish. At best, the memes and graphics on Facebook and Twitter will be just scientifically inaccurate nonsense; at worst they will be pseudoscience BS gobbledygook about “Blood Moons” and” Supermoons” etc. And inevitably, as happens with every astronomical event and story nowadays, the loony tunes brigade – hello, Jon Austin, tapping away there at the Daily Express – will gleefully predict the eclipse will trigger everything from earthquakes and wars to the Second Coming…

What’s actually going to happen? When will it happen? And what will you actually see?

Put very, very simply, at ridiculous o’clock in the morning (UK time) on Monday September 28th, the bright Full Moon will go dark, for a while, as it passes through Earth’s shadow. And that’s it.

Let’s get the nonsense out of the way, before the tin foil hat brigade have a chance to corrupt you with their breathless Facebook posts, exclamation mark packed tweets and migraine-inducing YouTube videos. The eclipse will not trigger any earthquakes, or wars. It will trigger *nothing*.  The eclipse “means” nothing. It will not make anything incredible or dangerous or cosmically significant happen, either down here or up there. anything happen. The Moon will not look “like a drop of blood!!!” in the sky. Don’t believe anyone telling you this stuff. They’re either genuinely scientifically ignorant, and are just repeating and sharing something they have read or seen without having any real clue what’s actually going on, or they are liars and charlatans, deliberately trying to worry or scare you, either for their own twisted sense of fun or to get hits and views for their pathetic websites and videos.

DURING THE TOTAL ECLIPSE THE MOON WILL GO DARK, AND THEN GET BRIGHT AGAIN. END OF STORY.

But why?

Well, you may remember that earlier this year there was a solar eclipse – an eclipse of the Sun – which was a huge media and public event. Although we were clouded out here in Kendal… not bitter about that at all, still… across the UK, and across Europe, hundreds of thousands of people thrilled to the sight of the Sun reduced to a crescent in the sky. This was caused the Moon passing in front of the Sun for a short time, blocking part of it from view. Exactly how much you saw blocked depended on where you were watching from. This is what was happening…

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Watching the solar eclipse required caution and special equipment – enough of the blindingly-bright Sun was left uncovered for it to remain far too bright to look at with the naked eye. The best views were through special eclipse glasses, through telescopes fitted with solar filters, or by looking at big images projected through telescopes onto screens. Yes, you have to be VERY careful watching solar eclipses. Get it wrong and you can seriously injure your eyes, or go blind altogether.

Watching a lunar eclipse, such as the one taking place on September 28th, is very different – and totally, totally safe.

Why? Because all that’s happening is the Full Moon is going to go dark – and you can look at the Full Moon without being blinded, can’t you? Yes, it’s dazzlingly bright, but it doesn’t physically damage your eyes. So watching the Full Moon go dark and then return to full brightness again is not dangerous; you can watch the lunar eclipse with just your eyes, safe in the knowledge that you are not going to damage your eyesight.

Here’s what’s going to happen.

In the early hours – I’ll get to how early shortly, I need to build up to it and break it to you gently! – the Moon will pass slowly through the shadow cast behind the Earth by the Sun. As this happens, the bright Full Moon will appear to get dark from the top left, as if a dark stain is spreading across it. When the Moon is fully inside the shadow it will appear very dark, although we can’t know in advance just how dark, or what colour it will appear (we’ll come to that later, too). Then, as it emerges from the Earth’s shadow, the Moon will appear to brighten again from the left hand side, the stain retreating, until the Full Moon is shining in the sky again.

Lunar_eclipse_sideview_v01

Sounds exciting! Well, to be perfectly honest, “exciting” isn’t the word that springs to mind when I think of a lunar eclipse. They progress very slowly, VERY slowly, and there’s no “magic moment” when something dramatic happens. Compared to a thrilling total solar eclipse – when the Sun winks out in an instant, plunging the world into darkness, and then returns in a blaze of light – a total eclipse of the Moon creeps along, and during the long total stage nothing appears to be happening from minute to minute. No, a total lunar eclipse is fascinating, and beautiful, and subtle and serene, but not exciting – at least for the general public. It’s exciting for amateur astronomers, legions of whom are already drooling in anticipation, and crossing their fingers for clear weather that morning. I know I am!

But… and this is the thing… this eclipse is not happening at a very user-friendly time. An ideal lunar eclipse happens in the evening, when people are still awake and are able to enjoy it without too much effort. This one is going to happen at a very unsociable hour…

clock

Yes, that’s right: the eclipse will begin at two o’clock in the morning. And it won’t end until half past five. I know… ugh….

So, this eclipse will not be observed by huge numbers of the general public. In fact, unless people make a special effort to watch it – staying up late or getting up early – it will only be seen by the following…

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But if you want to see it – and you must do, or you wouldn’t be reading this! – then here’s what you need to know.

To watch this eclipse you will need the following:

  • A good observing site
  • Warm clothing
  • Patience

Adding the following will make sure you enjoy the eclipse, rather than just see it:

  • Company
  • Hot flask
  • A pair of binoculars
  • A camera

GOOD OBSERVING SITE: a good observing site will be one which gives you a clear view of the sky from the south to the west, because that’s where the Moon will be in the sky. And because the Moon will be quite low in the sky throughout the eclipse, your site will need to have a fairly low, flat horizon in that direction too; any trees or buildings in that direction might hide the Moon from view. So, get somewhere dark, with a clear view across to the south and west, and you’ll be fine. If you can’t get somewhere like that, if you’re going to be stuck at home (and it’s a Monday, a work day for many, so a pre-dawn expedition out into the countryside might not be practical or possible) then just scout out your neighbourhood for the best observing site available. That might be your own garden, if you’re lucky, but maybe just walking to a nearby park, or up that hill up the road, will be enough. (Start looking now though, so you’re not scrabbling about on the morning!)

WARM CLOTHING: Come on, this is common sense really… two o’clock in the morning… it’s going to be chilly, maybe damp too. If you don’t dress warmly you will get cold and fed up really quickly, and the temptation to go back to bed – especially if the sky is partly cloudy and your view of the eclipse isn’t brilliant – will be strong.

PATIENCE: Oh, you’re going to need a LOT of that. Lunar eclipses move… very… slowly… the shadow creeps across the lunar disc in painfully slow motion, at least to the naked eye, and if you want to watch the whole eclipse, from start to finish, you’re going to be out there for three and a half hours. So, yes, you will need patience. Which is why the following items will really help you get though – and enjoy – the eclipse…

COMPANY: As is the case with most astronomical events, such as meteor showers, aurorae and comets, watching this eclipse will be a much more enjoyable experience if you watch it with others. Not just because you’ll be able to compare your impressions and views, but you’ll help each other stay awake at that crazy time of the morning! So go out with some family or friends and make a social event out of it. If you can’t persuade/convince/bribe anyone to come with you, take a radio, or turn on your car radio, just to have some background noise to help you stay awake. Trust me, it really will make a huge difference, and mean you’re much less likely to give up and go home early, especially if weather conditions aren’t ideal on the morning.

HOT FLASK: again, common sense. Take a long a hot drink (snack, too) just to help you stay awake and comfortable, as the time crawls by and the cold and damp do their best to send you back home early.

BINOCULARS: Although you absolutely can watch this total lunar eclipse with just your naked eye, and have a fantastic time, if you have or can get hold of a pair of binoculars, take them with you. They will give you a much clearer view of the Moon than your eyes can, and will really bring out the colours of the eclipse’s different stages, too. And you’ll be able to watch the shadow “eating up” lunar features, its craters and seas, as it crawls across the face of the Moon. (If you have a telescope, the same applies, of course).

CAMERA: It will be possible to photograph this eclipse if you have the right camera. We’ll look at that later on.

Right… that’s what you will need to watch and enjoy the eclipse. Let’s get down to the nitty gritty. Let’s talk times

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THE START OF THE ECLIPSE

If you intend to watch the whole of the eclipse, from start to finish, you need to be at your observing site of choice by 2am, because the eclipse will begin shortly after that. At 2am you will probably notice that the top left of the Moon already looks a little dark, a little grayish, because the Moon will already be in the outer part of the Earth’s shadow, so you might see some subtle shading. However, the eclipse proper will begin at around 02.10, when the Moon will start to be “eaten” by Earth’s shadow. This is when you’ll start to notice that the Moon looks a bit odd, a bit wrong, up there at the 11 o’clock position, and by 02.15 the darkening will be quite noticeable, especially through those binoculars you’ve taken along with you. As time passes the dark area will grow larger and more obvious, advancing across the Moon’s face from the top left towards the lower right…

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TOWARDS “TOTALITY”

As time passes, you will see the shadow of the Earth covering up more and more of the Moon’s bright face. To the naked eye it will look like the Moon is being eaten away, until it looks a bit like a Pacman in the sky. Through binoculars you will see that the Earth’s shadow isn’t completely black, but more of a dark reddish-grey, and you’ll be able to see lunar features through the shadow, too. By 02.45 the Moon will appear half-eclipsed, and will look very strange in the sky indeed. And as time marches on… or crawls on… more and more of the Moon will be covered up, until by three o’clock it has mostly gone, only a small “crescent” down at the bottom right will be left.

collage text_cr2_cr

This is one of the most fun times of the eclipse, as the time of “totality” approaches, and the visible part of the Moon’s bright face shrinks smaller and smaller. It’s fascinating to watch this stage through binoculars, so I strongly recommend taking some with you!

And then…

TOTALITY BEGINS…

Finally, at 03.11, an hour after the eclipse began, the Moon will enter total eclipse.

totality

Now fully immersed in Earth’s shadow, the usually brilliant Full Moon will go dark –

But how dark?

Well, the graphic I’ve used above shows the Moon so dark it almost isn’t there, but that’s just the way the software rendered the Moon. We can’t know in advance how dark the Moon will actually get, because every total eclipse is different. The colour and brightness of the Moon during totality depends on several things, particularly 1) how deep the Moon passes through the shadow, and 2) the state of Earth’s atmosphere at the time. If the Moon is passing through the centre of Earth’s shadow, the densest part, it stands to reason that it will appear darker than it would do if it was only passing through it closer to the edge. As for the state of the atmosphere, that matters because Earth’s atmosphere acts like a lens and bends some sunlight around our planet and onto the Moon, which is why it doesn’t vanish from the sky altogether. If the atmosphere has been mucked up by very bad weather, or a volcanic eruption perhaps, that can darken an eclipse. But come the Monday morning, we’ll just have to wait and see what we get!

What we do know is that between 03.11 and 04.23 the Moon will be totally eclipsed. This is when you want to have those binoculars handy, because they will emphasise whatever colours and hues there are on the Moon. If the eclipse is a “dark eclipse” it will look a dark muddy red-brown to the naked eye, possibly quite hard to spot in the sky. If it is a light eclipse, it will be more of a pinky-blue colour, and easy to see. Inbetween those two ends of the scale there are countless shades of orange, and red, and pink, with hints of blue, or gold, or even purple possible. All we can do is get out and look, and take whatever we’re given.

MAXIMUM TOTALITY

The Moon will be at maximum totality, its deepest into the Earth’s shadow, at around 03.45. At this point we might see the lower part of the Moon looking a little brighter than the top part, because of where the Moon will be in the Earth’s shadow, as this diagram shows…

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So, strangely, the Moon might actually look like Mars in the sky, with a reddish/orange disk and a lighter “polar cap” at the bottom. This is ironic because every year, EVERY year, nutters put out memes and images and “alerts” on social media trumpeting how Mars is going to “come close to the Earth” and so appear “as big as the Moon” in the sky. Utter, utter rubbish – it is impossible for that to happen. But on the morning of September 28th, around 03.45, the Moon might actually look a little like Mars in the sky…

Unlike the total phase of a solar eclipse, which flashes by in minutes, or sometimes just seconds, this total phase of the lunar eclipse is something you can enjoy at your leisure. You have time to drink in the view, to enjoy it both with your naked eye and through any binoculars or telescopes you brought along with you. Take in the colours of the eclipsed Moon itself, and how it looks in the sky too. Compare it to how different it looks to a normal, bright Full Moon. Try taking some photos. Or just stand there, enjoying the sight of the Moon looking funny and weird. Enjoy it however you want – but do enjoy it.

TOTALITY ENDS

The total phase of the eclipse will end at around 04.23, which is when the Moon will start to emerge from the Earth’s shadow. But even before this point you will probably notice the left hand side of the Moon starting to get lighter, the dark shades of the total eclipse brightening. At some point you will be aware that the left hand limb of the Moon looks silvery white again, or at least a lighter grey, and that will be it, the total phase of the eclipse will be over. But as the eclipse goes into reverse, there’ll still be lots to see as more and more of the Moon is uncovered. Through binoculars you will be able to see craters and seas and mountains on the Moon’s surface emerge from the shadow, as the Moon slowly returns to normal.

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By 05.20 – almost three and a half hours after it began – the eclipse will be almost over, with just a small patch of shadow darkening the lower right of the Moon, which will be quite low in the west by now. But as the lunar eclipse ends, don’t pack up and dash back home. Turn your back on the Moon, so you’re facing the east, and you’ll see several bright “stars” shining close together in the eastern sky…

planets no labels

Those “stars” aren’t actually stars at all – they’re planets!

planets labels

Now, if you took some binoculars with you, you’ll be able to see some pretty cool things before you head home. If you look at Venus, you’ll see it looking like a tiny crescent, like this…

venus

…and if you lift your binoculars to look at Jupiter, you’ll see some of its moons close to it, looking like tiny stars…

jupiter

…and really, that’s it. By now the sky will be starting to lighten in the east a little, as dawn approaches ( sunrise will be at 07.06), and the eclipse will be over. Hopefully you’ll then pack up your things and walk home, or go back indoors if you were watching it from your garden, satisfied with what you’ve seen.

Finally, a couple of notes about the weather and photography.

If your local weather forecast isn’t good for the morning (or if it is just wrong, and when you get up you found it lied when it promised you clear skies and it’s actually completely cloudy, or raining), you have a decision to make – you either put it down to experience, and just enjoy looking at other people’s photos on the internet, or you try to get to somewhere with a better view. That’s your decision. But if the sky is only partly cloudy, and you can see the Moon coming and going, it’s still well worth watching the eclipse, because as long as you get gaps in the cloud at the main times you will still see something.

As for photography, if you want to record your eclipse experiences you’ll need something better than the point-and-shoot “compact” camera (below, left) you keep in your bag, or your car. Photographed through one of those wide angle cameras the Moon is TINY, just a dot. You’ll need to use something a little more advanced, like a modern “bridge camera” or a digital SLR, or “DSLR” (below, right).

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They will let you zoom in on the Moon, giving you a larger image of it, and will also let you experiment with different exposure times and different ISO (what we used to call “film speed” back in medieval times) settings until you find a combination which gives you good shots of the Moon. As a rough guide you want to be taking shorter exposures before and after totality, when there is still some bright Moon visible, and longer exposures during the time the Moon is totally eclipsed, and darker. Just click away, trying different settings, until you get something you want to keep and would be happy to show others. (Oh, and use a time delay if your camera has one, and put your camera on a tripod, too, to hold it steady while taking your pictures. No tripod? Rest it on a beanbag, or a rolled up coat, on a wall or the top of your car).

…and that’s it. Enough! I hope reading this guide has left you feeling prepared for the eclipse. As I said at the start, a lot of absolute rubbish about this event is going to be doing the rounds soon, so if you have found this guide useful share it with your friends and anyone you think might be interested.

Good luck for the 28th – and let me know what you see!

One Response

  1. Who’s going to be where? I think i might go to Harrington in Workington or Allenby up the coast.
    Let me know!
    Titch

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