Telescopes

Question 1

Telescope

Answer 1

An instrument that magnifies distant objects and makes them seem closer

Question 2

Bodies in space

Answer 2

All the planets, stars, moons and other lumps of rock

Question 3

Lens

Answer 3

A piece of glass that bends light

Question 4

Image

Answer 4

Picture formed by light and focused on a screen

Question 5

Focus

Answer 5

Where light meets at a point

Question 6

Magnifies

Answer 6

Makes bigger

Question 7

Magnifying glass

Answer 7

A hand-held lens that magnifies small objects

Question 8

Optical

Answer 8

Used by our eyes

Question 9

Radio

Answer 9

Waves invisible waves given off by bodies in space, similar but different to light waves

Question 10

Array

Answer 10

A group of telescopes working together

Question 11

What is a telescope?

Answer 11

• 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.

Question 12

How a telescope works.

Answer 12

• 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

Question 13

Optical telescopes

Answer 13

• 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

Question 14

Magnification

Answer 14

• 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.

Question 15

Radio telescopes

Answer 15

• 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

Question 16

Arrays

Answer 16

• The telescopes are spread out so that each one collects slightly different information from the others. When the information is put together, we have a much better image than one telescope on its own.

Question 17

Telescopes in space

Answer 17

• The Earth’s atmosphere stops us from getting perfect images of bodies in outer space, even with the best optical telescopes
• Scientists have sent telescopes into space on rockets, where they now work as satellites
• Satellites go round and round the Earth in an orbit
• The telescopes take pictures of bodies in space without looking through the Earth’s atmosphere

Question 18

The Hubble telescope

Answer 18

• The most famous of the space telescopes is the Hubble Space Telescope
• It was sent into space in 1990 and is still sending fantastic pictures back to Earth
• Hubble has collected a huge amount of information about space, like accurate measurements of distances between stars and where stars get their energy from

Question 19

Salt

Ska

Answer 19

South African Large Telescope

Square Kilometer Array