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Transit Truths

Ok, guys, I need to tell you some things about this Venus Transit which is taking place next week. They might not be what you’re expecting or wanting to hear, but they’re the facts.

The Venus Transit is *everywhere* right now – on every space website, in every newspaper, and right across TV. The BBC is showing a special program all about it the night before, which is fantastic – ANY astronomy on TV is fine by me! – but I’m a bit worried that all this breathless coverage is rather giving the impression that the Transit is going to be a spectacle for the man , woman, child and dog in the street, like an eclipse or a meteor shower – something that anyone can see just by looking up from the litter-strewn, dog-dirt smeared pavement and think “Wow! Look at THAT!!”

I’m sure that there are lots of people out there expecting the Transit to look like a smaller version of a solar eclipse – a big black disc covering part of the Sun, making the sky go dark and causing birds to sing and tail-twitching lambs to run in a bleating panic to their mums.

Er, no.

The fact is, even if the sky is gloriously, fantastically clear where you live next Wednesday morning, as far as the UK is concerned, unless you’re a) either a vampire or an insomniac amateur astronomer, with b) specialist equipment, c) knowledge of solar observing and  d) a BRILLIANT location to view from, you won’t even know there’s anything going on.

Why? Because the Venus Transit is, essentially, the slowwwwwww passage of a small black dot across the blindingly-bright small disc of the Sun, AS THE SUN IS RISING. Even for people who know what they’re doing, who have the right equipment, it’s going to be an absolute pig to observe at all.

So please, everyone, let’s calm down just a little shall we?

The Venus Transit is going to be an amazing event for amateur astronomers with telescopes fitted with special solar filters, or image projection systems. But to see it they’ll have to crawl out of bed at 3.30am that morning, drive out of town past the houses of all the sane, sleeping people, to some godforsaken uninhabited place in the countryside, or on the coast, with a flat, featureless eastern horizon, where they’ll then wait for sunrise, and then squint at, and photograph, a tiny black disc silhouetted against the bright solar disc for an hour or so before it drifts free of the Sun’s limb.

If we manage to do all that, we’ll love it! It will be brilliantly exciting for us, after looking forward to it for so long, and as I sit here typing this post about it I’m honestly getting goosebumps thinking about it.

Yes, a Venus Transit is a fantastic astronomical event, a jaw-dropper for us astronomers. But someone has to be honest here: it’s not going to be seen easily by… well… you know, normal people.

But does that mean if you’re not an astronomer, and you don’t have a special telescope, or fancy equipment, that you shouldn’t try to see the Transit? No.

Absolutely not! :-)

Because this Venus Transit IS amazing – it’s nothing less than the chance to see another planet, another PLANET, moving between us and the Sun, briefly becoming visible against its blinding fiery face as a dark hole. It’s what astronomy, and the study of the universe, is all about. Two planets, and a raging star, in alignment, for pity’s sake..!

No. It’s definitely worth trying to see, and now I’ve pointed out  a few home truths about it, if you want to watch it, here’s what you need to do.

* Go out and drive around until you find yourself somewhere SUITABLE to watch the sunrise from on the morning of Wednesday June 6th – “suitable” means FLAT AS A PANCAKE TO THE EAST, WITH NO HILLS OR TREES, because the Transit will already be almost over as the Sun rises as seen from the UK, so watching the Transit will mean watching the first hour or so of sunrise. And if there are any hills, trees, buildings in the way you will very likely miss the whole thing.

* Having found a suitable observing site, you’re going to need something to observe the Transit WITH. But what? Well, sunglasses won’t darken the Sun anywhere NEAR enough to let you see Venus silhouetted against its disc. And for the love of God, don’t try smoked glass; we stopped using that to observe the Sun back when Noah was building his boat. A piece of VERY dense welding glass would work, but only for very brief naked eye glimpses of the Sun, you absolutely mustn’t put it in front of binoculars or a telescope and lo0k at the Sun that way.

And seriously, if you have even considered for a split second looking at the Sun straight through a pair of binoculars, or a telescope, then get off my blog. No, really, just go, because that is so slap-across-the-face STUPID that you don’t deserve to be reading this. It should be obvious to EVERYONE that if you magnify the image of a blindingly-bright, searingly-hot light in the sky it’s going to BURN YOUR EYES OUT OF YOUR ******* SKULL!!!!!

If you’re still reading then that must mean you’re not a stupid person, so I’ll tell you how to observe the Transit safely! :-)

Many astronomers – professional and amateur – will be watching the Transit through their telescopes, but those telescopes will be fitted with very special filters, made of glass or a a foil-like film that reduces the light from the Sun to a tiny, teeny frction of its usual brightness, thus allowing them to see features on it like sunspots, and also see Venus as a black disc silhouetted against its face. These filters are pretty specialised bits of kit, and unless you’re an amateur astronomer already you won’t know where to get them from or how to use them properly, so forget about them ok?

Other astronomers will be using their telescopes in a different way – and the key word here is PROJECTION. They’re going to line up their telescopes with the Sun, WITHOUT LOOKING THROUGH THEM, and then put a piece of card in front of the eyepiece. The telescope will then project an image of the Sun onto that piece of card, and they’ll be able to see Venus’ disc very, very clearly against that disc.

This is how the aforementioned man, woman, child or dog in the street can watch the Venus Transit. You probably won’t have a telescope, but I imagine you have – or have access to – a pair of binoculars? So let’s go with that.

You’re going to need that pair of binoculars,  their lens caps (oh they’re around somewhere, just look for them!), some card, and a bit of common sense.

First, put the main lens cap on the front of one side of the binoculars, leaving you effectvely with a short, stubby, low-magnification telescope. Next you need to aim the binocs towards the Sun, but without looking through them. This is really easy actually – just point them very roughly towards the Sun and then jiggle and wiggle them about until a bright circle appears on the ground, or wall, or whatever surface is behind the binoculars while you’re moving them. This is actually a projected image of the Sun. See that, and the hard work is done!

Now you know how to line the binocs up with the Sun, all you have to do is put a piece of white card or something like it behind the binocs and focus them until the Sun’s image is sharp and round. You might even see some sunspots! Move the binocs away from the ‘screen’ until you have a good-sized image, and that’s it – you’re ready!

Then, on the Wednesday morning, go to your observing site for quarter to five, look to the east, and wait. When the Sun cracks the horizon, start projecting its image, and voila, there you’ll see the dark disc of Venus against the Sun’s bright face. Something like this…

Simple really! :-)

Then what?

Well, take pictures! Get your digital camera, and just snap away, something will turn out ok.

Of course, if your local astronomical society is holding an observing event for the Transit, get yourself along to it and enjoy the show. The people there will be more than happy to show you Venus’ disc silhouetted against the Sun. But given the time of this Transit you might well be on your own this time, so follow the advice above and you won’t go far wrong.

And if you’re in some other country, your Transit timings will be different – you might even be able to see the whole thing. If you can, I urge you to track down a local astronomy group and watch it with them, you’ll get a superb view and meet some fascinating people with fascinating equipment and knowledge.

Good luck!

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One Response

  1. Good interesting post. Only one problem with it. No self-respecting vampire will be observing Venus transiting the sun, because any vampire still around when the sun rises is stupider than folk who burn their eyes out staring at the sun through binoculars.
    The sun destroys vampires (unless they’re that strange sparkly vampire which seems to be en-vogue).

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