Tools of Modern Astronomy Chapter 21 Section 1 Pages Chapter 21 Section 1 Pages

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

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

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

Reflecting Telescope

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

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

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

Observatories Free of Clouds No light Pollution Less Atmosphere

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

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

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

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?