Telescopes Flashcards
1
Q
Telescope
A
An instrument that magnifies distant objects and makes them seem closer
2
Q
Bodies in space
A
All the planets, stars, moons and other lumps of rock
3
Q
Lens
A
A piece of glass that bends light
4
Q
Image
A
Picture formed by light and focused on a screen
5
Q
Focus
A
Where light meets at a point
6
Q
Magnifies
A
Makes bigger
7
Q
Magnifying glass
A
A hand-held lens that magnifies small objects
8
Q
Optical
A
Used by our eyes
9
Q
Radio
A
Waves invisible waves given off by bodies in space, similar but different to light waves
10
Q
Array
A
A group of telescopes working together
11
Q
What is a telescope?
A
- Telescopes are mainly used for looking into space and gathering information about what space is like.
- An Italian scientist called Galileo Galilei invented a telescope
- We were then able to look far into space and collect new information
- We discovered planets we didn’t know about, and we found that some of the planets have moons
- Today we know many facts about the bodies in space, like what they are made of and how they move.
12
Q
How a telescope works.
A
- There are different types of telescopes
- The simplest kind allows you to look through it, and it will make what you see look bigger and clearer.
- A simple telescope has the following parts:
- A long tube, made of metal or plastic
- A glass lens at the front end, nearest to what you are looking at (called the objective lens)
- A second glass lens, near your eye (called the eyepiece lens)
- The objective lens collects light from a distant object and brings that light, or image, to a point of focus.
- An eyepiece lens takes this bright light and ‘spreads it out’ (magnifies it) so that we can see it.
- A magnifying glass works in the same way
- When you use the two lenses together, you have a telescope that makes distant objects much easier to see
13
Q
Optical telescopes
A
- Optical telescopes are telescopes that we look through
- Binoculars and camera lenses are types of optical telescopes
- When looking at bodies in space, we have to look through the Earth’s atmosphere
- The gases of the Earth’s atmosphere make the images we see look fuzzy
- This is why most of the large telescopes used by scientists are placed high on mountains, where there is less atmosphere to look through
- Optical telescopes are used mainly at night
- Research telescopes are usually placed in country areas where there is less light than in towns
- Scientists take photographs through optical telescopes, which they study closely to get new information
14
Q
Magnification
A
- The telescope’s job is to make a very small object look bigger so we can see the object clearly
- How big the telescope makes it look is called the magnification
- If a telescope has a magnification of ten times (x10), the object looks ten times bigger than without the telescope
- If it has a magnification of x100, the object looks a hundred times bigger
- So, the bigger the magnification, the bigger the object looks.
15
Q
Radio telescopes
A
- Bodies in space, like stars, planets, black holes and even galaxies, give out radio waves which we can’t see with our eyes.
- Radio waves give us new and different information about those bodies
- We need to use a different kind of telescope to find and record the radio waves
- We use radio telescopes
- Radio telescopes do not have lenses or mirrors, and we don’t look through them
- They have different designs to collect different types of radio waves, but you will see they usually have a bowl or dish to collect the radio waves.
- Scientists can make pictures from radio waves. Radio telescopes need to be far away from cell-phone and radio networks
- A radio telescope on its own can only collect a small amount of information, but a group of radio telescopes together can collect much more information
