1. Honors Ch. 28.1 Pg. 747-752

2. Almost everything we know about the universe (space) comes by studying light from distant sources. Light from what?

3. Light is a type of electromagnetic radiation (visible light) Other types of electromagnetic radiation Radio waves Microwaves Infrared rays UV radiation X-rays Gamma rays

4. Light that we can see. Longer wavelengths = less energy & redder color Shorter wavelengths = more energy & bluer color

5. Spectrum – different types of light give off different “spectrums” (bands of color) 3 types Continuous spectrum Absorption spectrum Emission spectrum

6. Produces an uninterrupted band of color

7. Produces a band of color but with some dark lines of missing color

8. Only produces a few bright lines in the spectrum

9. The type of spectrum tells us the types of elements that are in the object that is producing the light. We can figure out what the object is made of! Most stars produce light in the absorption spectrum. Article to read as a class… Search For Alien Life Project

10. Has anyone ever heard of it? Has anyone ever heard it? Doppler Shift Animation

11. Think of a train horn or ambulance siren as it moves toward and passes you. Does it sound the same? Why?

12. The sound of the horn or siren sounds higher (pitch) as it comes toward you. It sounds lower as it moves away. We perceive the sounds wavelengths as shorter and then longer.

13. The Doppler effect also occurs with light waves. In astronomy, the Doppler effect is used to determine if an object in space is moving toward or away from Earth. This redshift and blueshift will come up again when talking about our universe….

14. Telescopes Refracting telescopes (visible light) Reflecting telescopes (visible light) Telescopes at other wavelengths Space telescopes Why use a telescope? 1. Attach different detectors to telescopes to observe all wavelengths, especially the ones humans cannot see 2. Brings more light to a focus than the human eye can 3. Allow astronomers to use specialized equipment 4. Telescopes can be used to make time exposures with cameras and other imaging devices

15. Refracting telescopes – Uses lenses to focus light on a specific spot and then magnify the image

16. Reflecting telescopes – use lenses and mirrors to focus and magnify light While refracting and reflecting are both still used today, the majority are reflectors.

17. Both refracting and reflecting telescopes help astronomers because 1) they help gather light from far away objects 2) they help make objects more clear (resolve power) 3) the help magnify objects (make them appear bigger)

18. Astronomers observe the universe at wavelengths the human eye cannot detect. Same goal: bring as much radiation as possible to a focus! EX: Infrared and UV using mirrors X rays using special designs Gamma rays cannot be focused, so telescopes can only determine the general direction from which the rays come. Radio waves using a large dish with receiver Interferometry – linking separate telescopes together to act as one telescope

19. Are used to detect radio waves from space objects. Radio telescopes have recorded awesome events such as two galaxies colliding!

20. Telescopes are placed in space so that the Earth’s atmosphere can’t distort the image. They produce more clearer images than land telescopes.

21. Hubble Telescope – 2.4 meters long, has 10 billion times more light-gathering power than the human eye. It has produced spectacular images of planets, stars, galaxies, and deep space.

22. Hubble Space Telescope Far Ultraviolet Spectroscopic Explorer Chandra X-Ray Observatory Spitzer Space Telescope

23. Spaceflight International Space Station

24. NASA technology that has been passed to commercial industries for common use Laser angioplasty Cardiac imaging system Advanced pacemaker Infrared thermometer Thermal video Body imaging Skin damage assessment

26. 1. Which color has the longest wavelength? A. red B. blue C. green D. orange

27. 2. Which of the following refers to the change in wavelength that occurs when an object moves toward or away from a source? A. Doppler effect B. chromatic aberration C. spectroscopy D. wave theory of light

28. 3. What will happen to an object’s wavelength as the object moves toward you? A. The wavelength will be shortened. B. The wavelength will be lengthened. C. The wavelength will not change. D. The wavelength will vary.

29. 4.A reflecting telescope produces an image using a(n) ____. A. concave mirror B. lens C. prism D. antenna

30. 5. A radio telescope produces an image using a(n) ____. A. concave mirror B. lens C. prism D. antenna