How Can I View the Venus Transit?

@Julien wants to know how he can view next month's Venus transit. Not sure what that is? Check out this post first.

On June 6th 2012 (for those of us in the UK), as the Sun rises the planet Venus will, from our point of view, make its way across the Sun's disc. Of course, looking at the Sun without any kind of protection is a monumentally stupid thing to do, but this is also a rare astronomical event that none of us alive today will ever get the chance to see again. So how can we give ourselves a chance of witnessing this spectacle without destroying our eyes in the process?

There are a few ways you can take part, and I'll give the most important one first:

1. Find someone who knows what they're doing and make sure you're hanging out with them during the early morning of June 6th

Yes, I know it's obvious, and I know it's probably not an option for many people, but this really is the safest and most sensible option. If you have an astrogeek friend - and I mean a proper astrogeek, not some wannabe astrogeek, as you really don't want to entrust the future of your eyesight to someone who only thinks they know what they're doing - then throw a Venus party and get them to organise the sciency bits.

2. Make a pinhole camera
This is one of the safest ways of allowing a bunch of people to view the Sun, and if you set it up correctly you should be able to see Venus as a little black dot. While this is actually really easy to do, I'd spend a bit of time practising beforehand so that you can get the best image possible. Here's how to do it:

You need two things, and both of them are sheets of stiff card.
  • In one of them you need to make a pinhole* (this is why it's called a pinhole camera...).
  • Hold this sheet up so that the Sun's light can shine through the pinhole (DO NOT be so numptyish as to look through the hole while you're lining it up. Just move it around a bit until it works).
  • Hold the second (unholy) sheet of card so that the light from the Sun that's shining through the pinhole falls on it. It should be held parallel with the first sheet of card.
  • Move the second sheet of card towards or away from the first to adjust the image.
If you're feeling imaginative you might be able to make a stand for the card. Also, you'll get a better image if you can somehow shield light other than that coming through the hole from falling on the second piece of card. One idea I've come across is to suspend the holy card in a piece of thick fabric (e.g. a curtain).

3. Use eclipse viewing glasses
If you really must look directly towards the Sun, then at least make sure you're wearing adequate protection when you're doing so. A standard pair of sunglasses WILL NOT do. You need some purpose-built eclipse shades, like these ones. Such specially designed filters remove around 99.99% of the Sun's light (including the harmful infrared and ultraviolet ends of things), allowing you to view in safety and comfort.

Even so:
  • DO NOT look at the Sun for prolonged periods, even with eclipse glasses on.
  • DO NOT use the glasses if the lenses are scratched or appear damaged in any way.

4. Buy a solar telescope
If you're feeling flush, you could fork out £600 on a specialist solar viewing telescope. For a fraction of the price (around half), you could go for a 'sunspotter'. At around £300 these seem to be much more amateur-friendly and allow a view of the Sun without having to look down an eyepiece. I'd love one, but don't have the cash to spare and can't work out where to buy one anyway. Further down the price scale is the SolarScope at around £50 for the cheapest model. It looks like you can get hold of one here.

6. Watch the webcast
Lets face it, given the weather so far this year, it'll probably be raining. Never fear, though, for there will be a live remote webcast from the Mauna Kea observatory in Hawaii. Stick this link in your bookmarks:

A note...
It is possible to view the Sun through your own telescope or binoculars (either directly or by projecting the image onto a screen) with appropriate filters on the business end of whatever you're using (that's the end that points towards whatever you're viewing, NOT just the eyepieces), but I wouldn't encourage this for anyone who's not experienced and knowledgeable in such things. I certainly won't be trying it as getting it wrong can cause untold damage to your equipment as well as your eyes.


If you're in any kind of doubt whatsoever, then assume that pointing your eyes in the direction of the Sun is the wrong thing to do. DO NOT look through the eyepiece of ANY telescope or pair of binoculars or any other gizmo unless you're completely confident that the right bits are appropriately filtered.

* If you're not sure how, I'd suggest using a pin.


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