1. Telescopes Science 9

2. Telescopes The main purpose of a telescope is to gather light Images that form can be recorded by taking a picture or a video

3. Types of Telescopes Refracting telescopes bend light (oldest) Reflecting telescopes uses a mirror to gather light – Larger ones are located in observatories located on tops of mountains and deserts where the air is thin and less distortion of images occur – The Hubble telescope is located in outer space which gives much more detailed views of the stars

4. Using Radio Waves to Understand Stars Radio receivers can receive radio waves from stars Radio waves are part of the electromagnetic spectrum (radio waves, visible light, X rays, etc.) All these waves travel at the speed of light The energies become greater as the waves become smaller A third type of telescope is a radio telescope

5. Radio Telescopes Superior to other telescopes because waves can travel through clouds as well as any time of the day Usually, it is in the shape of a dish and it collects waves More than one radio telescope can work together – This is called an array

6. The Problem with Earth’s Atmosphere Although the Earth protects us from harmful rays, it poses problems for astronomers wanting to collect all wave energy from stars Satellites are sent into orbit to collect such information The Infrared Astronomical Satellite (IRAS) detects trace amounts of heat from objects in space