Brief talk, discussion and video on radio astronomy
Talk based on the following, if there's questions at the end have a Q&A session. We did this on 11th October so it was significant and followed it up with a 4 minute video from Youtube (resources).
People have looked at the stars for a long time with their eyes and telescopes, but in the early 1930s- about 80 years ago- an engineer working on radio communications across the Atlantic realised that some annoying interference was actually coming from the sky. At first he thought it was the sun, and then discovered it was coming from the middle of the galaxy, where we now think a massive black hole is tearing things apart and giving off lots of radio waves and light as it does so.
In space thereâ€™s lots of dust clouds, so there are things out there that we canâ€™t see because the dust clouds block the light. But radio waves can go straight through the clouds, so a radio telescope can let us see them. And it's the same with rain clouds- we can still use a radio telescope on a cloudy night. This means itâ€™s worth building them to add to what we know about the universe. And itâ€™s not just about seeing behind the clouds- there are things that weâ€™ve discovered using radio astronomy that we never knew about before like pulsars- collapsed stars thatâ€™re spewing out beams of particles and radio waves and spinning round, so the beams sweep across space like a lighthouse and radio telescopes pointing at them hear the "flashes" as regular clicks that can be lots per second.
In 1955, it was decided to build a radio telescope near Manchester. This became the Lovell Telescope, at Jodrell Bank Observatory. At the time, it was the biggest in the world. It is still the third largest fully steerable radio telescope. It started working in summer of 1957, but it was just before midnight on October 12th that it first hit the news when it managed to find Sputnik 1, the worldâ€™s first artificial satellite that the Russians had launched a week before.
The telescopeâ€™s called the Lovell Telescope after one of the people who helped make it- Bernard Lovell. When radio astronomy was first discovered, he was around cub age. He died this summer (2012), aged 98. So as well as this week being the anniversary of Jodrell Bank becoming fully operational, this yearâ€™s also when the man who built it, and lived through the start of radio astronomy, died.