Transcript

INSTRUCTOR:

So as you learn more about the night sky looking around just with your eyes, you might start thinking about some equipment to use. Binoculars are the first obvious thing, but there's also a huge variety of telescopes out there. And choosing which one can be quite a difficult choice. It's worth having a go with lots and lots of different types.

The first type of telescope that was developed, and one of the most common, is a refractor. And this particular type of telescope's nice that simple. You've got a lens up at the front here. The light passes down the telescope itself, and then the eyepiece that you're looking in is down at the back here. So simple, but very, very effective.

Your next step up is then a Newtonian style reflector. So this style of telescope, again, your light is obviously coming in at the front. But this time, it's travelling all the way down the tube to the main mirror that's all the way down here at the back. The light then comes back up, bounces off the little mirror mounted in the tube here at a 45 degree angle, and out to your eyepiece here.

So these are the two most common types. But telescopes are progressing very, very rapidly with their technology, just as the rest of astronomy is. And so there's various different combinations now that use both mirrors and lenses. And we've got one of those combinations here. This is what's referred to as a Schmidt-Cassegrain. You've actually got a lens right at the front, but then your large primary mirror at the back. And that primary mirror actually has a hole in it. So as your light bounces up and down the tube, your eyepiece again is down on the back here.

On this particular telescope, we either have an eyepiece on the back of it, or we quite often attach a camera, because we're here today in the George Abell observatory actually on campus in Milton Keynes at the Open University. So you don't have to do all of your astronomy from Teneriffe. You can do a lot from the UK as well.