1. Tools of Modern Astronomy Chapter 21 Section 1 Pages 716-718 Chapter 21 Section 1 Pages 716-718

2. Main function- is to collect and focus different types of electromagnetic radiation. Telescopes Refracting Reflecting

3. Uses two convex lenses (thicker at the edges) to gather large amounts of light and focuses it into a small area. 1609- Galileo used one to look at the sky. The larger the lens the more light it can collect Refracting Telescope

5. Reflecting Telescope Uses a mirror instead of an objective lens. Focuses large amounts of light into a small area. 1668- Newton build the first. Today, this is the largest visible telescope.

6. Reflecting Telescope

7. Used to detect radio waves Most have a curved surface 305 m in diameter The surface concentrates the faint radio waves towards an antenna. The larger the telescope the more it can collect. Radio Telescopes

8. Long Wavelengths------Short Wavelengths Radio/Infrared/Visible/UV/X-Ray/Gamma Other Telescopes

9. Observatories A building that contains one or more telescopes. Most are on Mt Tops- Less atmosphere and less light pollution from cities. Mauna Kea- Best Site 4,200 m above sea level

10. Observatories Free of Clouds No light Pollution Less Atmosphere

11. Satellites Earth’s atmosphere blocks out most of the short wavelengths on the Electromagnetic spectrum. (U-V, X-Ray and Gamma Rays) Rely on satellites to detect these forms of radiation. Very Detailed Images

12. Hubble- Reflecting Telescope –Collects- IR, Visible and UV Chandra- X-Ray Observatory –Detects X-rays. Satellites

13. D. Hubble B. Einstein C. Galileo A. Wagner Which scientist was the first to use a refracting telescope?

14. D. cheaper to build B. colder at this altitude C. less light pollution & air A. closer to the stars Why are most observatories on Mountain tops?