1. Ch. 28 Sec. 1 Tools of Astronomy

2. Tools  Radiation  Light is the best tool used to observe and learn about the universe  Before telescopes, scientist used light from stars  Travel as waves  Radio waves, Infrared, Visible light, UV rays  Humans only see visible light  Classified by frequencies  As frequencies increase, the wavelength decreases

4. Tools  Telescope Telescope  First used by Galileo  4 Main Benefits  1) Different Attachments  Observe all wavelengths that objects emit  2) Light to a Focus  Takes distance light and brings it to one point for human eye to see

5. Telescope  3) Use of specialized equipment  Photometer used to measure intensity  Heat and strength of stars, Novas  4) Time Exposures  Selected time intervals can gather “photographs” to faint to be seen from human eye

6. Telescope  Refracting  Used a lens to bring a light into focus  Faint ring around image is distortion of light

7. Telescope  Reflecting  Bring light into focus using mirriors  Most scientific telescopes are located high altitude for less atmosphere

8. Radio Telescope: of different Wavelengths  Bring in as much radiation into focus  Dish that reflects all waves to a focus above the dish

9. Radio Telescope: of different Wavelengths  Interferometry  Process of linking separate telescopes together

10. Others:  Space instruments are used because Earths atmosphere blocks many different rays  Hubble Space Telescope  Use til 2010  Picks up sharp images