Science, Maths & Technology
• Activity
• 10 mins
• Level 1: Introductory

# Measure the Astronomical Unit and watch the Transit Of Venus

Updated Tuesday 25th March 2008

Explore and watch the Transit of Venus - and measure the Astronomical Unit

### Watch the Transit

Watch this video of the last transit, which will allow you to get the timings you need. The video will also explain how to use the interactive to input your measurements.

## Watch

Watch the Transit

Lucie
Well I’m here looking at the website Open2.net joined by Michael from the Open University.  Michael, how are the timings entered onto the website?

Michael
It’s very, very simple.  All you need to do it click on the link, measure the AU and straight away you’ll be able to enter our interactive astronomical unit calculator.  First thing you need to say is are you working from the results coming from the TV, so that’s our feed from Egypt.  But for the sake of argument let’s say that you’re at one of the events around the UK, enter your own observation and click on the forward arrow.

Lucie
Right so I see there’s some timings here on the website.  Does that mean you have to adjust your times depending on where you are in the UK?

Michael
Absolutely, so if you’re in Scotland, for example, you might need to increase your timing for example to 22 seconds.  Down in Cornwall it’s minus 12.

Lucie
Right ok then you click the forward button and your result, you have to enter it there.

Michael
Very simple, there’s a box to type in the hours, there’s a box to type in the minutes and a box for the seconds.

Lucie
That’s great, and so our website will do all the fiendish maths for you.  Back to Adam.

Terrific, Ok Andy, how’s it getting on can we see the picture from Egypt please?

Andy
It’s nearly there isn’t it?

There, it’s very close but you can still see a little bright bit.

Andy
Definitely let’s see how it looks here shall we.

Yes can we see the white light one from here?  Again very close, very close.

Andy
That probably is closer isn’t it?

Right what does it look like in Much Hoole?

Female speaker
Well we’re having a fantastic time here in Much Hoole, Adam, with everyone from professional astronomers and PhD students, to school children from New Zealand to Tarleton just up the road.  What are you guys up to?

Female speaker
We're just getting ready to measure the third contact.

Female speaker
How are you going to do that?

Male speaker
We’re going to be using stop watches.

Female speaker
Well we’re coiled springs here in Much Hoole.  Back to you in Greenwich.

Thanks very much, now, what do you think Andy, it’s very close.  Can we see the white light one too?  White light one?

Andy
It’s almost there isn’t it?

It’s so difficult.  I reckon, is that like, it’s very tiny.

Andy
Yeah on the white light image from here.

I reckon it’s about, right, all you don’t forget to shout now when you think it happens look on the big screen.

Andy
It could be any time now, any time now.

I reckon there’s still a little sliver of orange light.

Andy
On the Egypt one there’s still a gap but I think the one from here that’s probably contact right about now.

Are we at first here?

Andy
I think so yes, I think the contact is first here.

Well, it does look like it, nobody’s said now yet.

Andy
In Egypt, it looks as though the edge of the sun’s almost sort of bulging round it, sort of optical illusion.

It does doesn’t it?

I reckon it’s about now, I haven’t heard a single now from the crowd, not one.

Crowd
Now!

Ah we’re getting them, yes.

Andy
Look there it looks as though it's contact there.

It’s touching.

Crowd
Now!

Andy
I think that’s it.

Right, right lets go over to Egypt, Paul what’s it like there?

Paul
Well, we’re 28 seconds behind you here so we’re going to get contact any time now as you can see feverish activity despite the intense heat, everybody’s getting ready, video, TV, people are drawing it just like Cook did, getting ready.  Back to you Adam.

That’s wonderful well I reckon we’ve got it, I reckon we’ve got first contact in Egypt and let’s have a look at the telescope here, I think we’ve got first contact here.  What’s happening in Much Hoole?

Frenzied activity.  Ok, hey look it’s got to be...

Andy
I think it’s there I think the third contact is there.

Okay, Lucie have you got new results in?

Lucie
Hi Adam, we’re just waiting for the first results to come in now.  We’ve had quite a few images being sent to our website and people contacting the forum to discuss their results.  We’ve got a couple of images here to show you.  So the first one here unfortunately an observer had a bit of cloud there but they’re seeing towards the end of the transit and the next one, got a couple more images there.  So it’s looking really, really good, this is a lovely clear image showing no cloud at all. So we’re just waiting for those first observations and first timings to come in now.  Back to you.

Excellent well we’ll come back to you in a minute to try and get some results.  It was much easier to see the third contact than the second wasn’t it Andy?

Andy
I think it was much easier yeah.

It seemed to, I mean we might have disagreed by a few seconds but it was much harder.

Andy
It seemed easier to see when that contact actually happened didn’t it, they must be seeing that now in Egypt.

Well I would hope so, can we go back to Egypt?  Paul?

Paul
Hi

Andy
Well I think this is the image from Egypt isn’t it and it looks as though they’ve definitely had the third contact there