Part of the team that created the Hubble Space Telescope, John Zarnecki...
Part of the team that created the Hubble Space Telescope, John Zarnecki looks back at his time on the project - and shares some of the photographs.
- Duration: 5 mins
- Published on: Tuesday 12th June 2007
- Introductory Level
- Posted under: Astronomy
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Now let me move forward a few years, in fact to 1978. It was hard to get jobs in the late Seventies in the academic world so I moved to a company called British Aerospace in Bristol and they were working for the European Space Agency on a project called the Large Space Telescope. So I joined that project and I was responsible for overseeing the heart of a camera that was going to work at the focus of this telescope. Now you will know the telescope better as the Hubble Space Telescope, as it was later christened, and the camera was the Faint Object Camera. And unlike my Woomera experience, this was working mostly in the visible part of the spectrum and also the ultraviolet.
Now Hubble has been absolutely vital to astronomy because it has enabled us to see further and with greater clarity than ever before. At the time, the camera that we built was the most sensitive camera on Earth or in Space. And it turned out to be the longest-serving camera in orbit. It was only removed in 2002 after twelve years of operation. It is still a world record. It could measure, for example, the width of a human hair at a distance of one kilometre and it was so sensitive it could have detected a candle at half the distance to the moon. Now after a successful launch in 1990 – there it is going up on the Shuttle – Hubble was deployed from the cargo bay of the Shuttle. There it is with those enormous solar arrays to give it power. And we sat and we waited. Now I don’t have to tell you that Hubble had a few teething problems.
All right. Which bloody fool left the lens cap on!
Well, it wasn't quite like that. It was more a problem with the mirror, beautifully manufactured and figured – to the wrong shape. Nothing to do with me, Guv, honestly! My bit worked perfectly from the start.
So this is obviously an example of where our fingers weren't crossed tightly enough. Now by that time I had moved on to other projects but still I was desperately disappointed that it appeared to have failed. Well, as we know, eventually NASA launched a rescue mission three years later in 1993. They put on a correcting lens in front of the mirror and it worked fabulously. It was really worth the wait. Here, for example, is one of the early images from the Faint Object Camera that I worked on. This is Pluto and its satellite Charon, beautifully resolved as never before. And also, for the first time, we were able to see Pluto and to see some structure rather than just a blur of light. But of course Hubble is best known for some of the beautiful images that it produces, some of the visual images. Let’s have a look at a few of them. This is a spiral galaxy. You can see some of the stars and some of the beautiful structure there. A nebula with different colours representing different elements, different temperatures. The famous Orion Nebula. You can see Orion’s Belt and Sword with the naked eye. This is a region where stars are forming out of gas and dust before our very eyes. And one of the most breathtaking achievements of Hubble was something called the Ultra Deep Field. What Hubble astronomers did was to choose a tiny part of the sky – in fact it was the size of a pinhead held at arm's length – a perfectly anonymous piece of sky and we are homing in on it. And Hubble stared at it for one million seconds to build up an image.
And what did it find? Well, as it stared and built up the image it found that this apparently anonymous piece of sky actually was filled with thousands of galaxies. Each of these is a galaxy and each galaxy contains literally billions of stars. There are some people who believe now, I think with some confidence, that of these stars, maybe as many as ten per cent of them, also possess planetary systems. So I think you can see there the implication is pretty mind-boggling. And there is something else. You know that, when we look at the Sun, we are actually seeing the Sun as it was about eight minutes ago. That’s how long it takes light to reach us. If we look at some of the nearby stars they are light years away so we are seeing them as they were a few years ago. With some of these objects in the Hubble Ultra Deep Field, these are some as far as thirteen billion light years away. So we are seeing them as they were thirteen billion years ago. And, as I am sure as you all know the Universe is merely fourteen billion years old. So we are really looking back with Hubble, far, far back to close to the origin of our Universe. So Hubble really is the closest thing that we have to a time machine. It really does help us to look back in time.
With thanks to:
- JAK (Hubble cartoon)
- Evening Standard
The Open University Lecture 2007
This is part 4 of 10
Next: chasing a comet
Copyright & revisions
Originally published: Tuesday, 12th June 2007
Last updated on: Tuesday, 26th June 2007
- Body text - Creative-Commons: The Open University
- Video - Copyrighted: The Open University
- Audio - Copyrighted: The Open University
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