1. Chapter 18 Exploring Space

2. Section 1 Observing the Sky How do we observe space from Earth? Un-aided eye Binoculars Telescopes Most ancient astronomers spent countless nights observing and mapping the sky.

3. Early Astronomers

4. Ptolemy Copernicus Brahe Kepler Galileo Newton Hubble Your homework assignment: Write a summary statement about the contributions of each scientist to early astronomy.

5. Telescopes Single purpose of telescopes is to gather and focus light!

6. 9 minutes Telescope video

7. Optical Telescopes Refracting Telescope - uses convex lenses to magnify objects in space Large ones no longer built because lenses will distort over time due to gravity. Small ones good for beginners

8. Reflecting Telescopes- uses MIRRORS and eyepiece lens to magnify. Better quality, easier to build big ones. Reflectors

9. MMT (Multiple Mirror Telescope) - reflector with many mirrors. High quality, combine smaller mirrors for image Hubble space Telescope- Highest quality, no atmosphere to distort light, very dark!!!

10. Tips for using telescopes Get on a hilltop or mountain peak Get away from any lights Must be clear!! Best if it is really cold!!

11. Limitations of ground based Telescopes Telescope viewing distortions caused by movement of air particles in atmosphere and light pollution. This is why stars “twinkle:

12. Atmospheric distortion

13. Observatories Kitt Peak Observatory, Arizona

14. Mauna Kea, Hawaii

15. Observatories Worldwide

21. World’s largest telescope Keck Observatory, Hawaii Hubble Space Telescope Comparison of Galaxy NGC 1232

22. All objects in space give off ELECTROMAGNETIC ENERGY We can only see ROY G BIV, the rest are not visible, but can be detected with special types of telescopes to learn more about our universe.

24. Radio Telescopes Telescopes that detect radio waves from objects in universe Benefits over regular telescopes: Can be used day or night can be used in most weather conditions can detect objects not visible in space Downfalls- not a clear image

25. Arecibo, Puerto Rico VLA (Very Large Array) New Mexico Largest single telescope in world 27 dishes over 17 mile area

26. West Virginia

28. iiii Other types of telescopes X-ray Gamma ray Infrared Ultraviolet All must be detected by telescopes in space because atmosphere blocks these wavelengths

29. Rocket Science Our method of transportation to get into space is the rocket! Why can’t regular airplanes with jet engines travel to space?

30. Fathers of Rocket Science Tsiolkovsky- developed theory that escaping gas could generate force to leave Earth’s gravity Goddard- launched first liquid fuel rocket 1926 Von Braun- built V-2 rocket for Germans in WW II, defected to U.S. to further aid rocket science

31. 6 minutes

32. How do rockets work? Works by Newton’s 3 rd Law (Every action has a reaction) THRUST created by combustion of fuel under enormous pressure, gas rushes out of the rocket

33. Solid Fuel Rockets- Uncontrolled burn, used for launching rockets Liquid Fuel- controlled burn, used to maneuver in space.

34. How liquid rocket fuel works Consists of fuel and oxidizer Liquid fuel is some form of hydrogen Oxidizer is some form of oxygen Oxidizer is used to ignite the fuel Can be controlled to burn when needed

35. Solid rocket fuel Consists of putty-like mixture of fuel and oxidizer. Once ignited, they cannot be controlled or stopped. Fuel used for initial blast-off of rockets.

36. Satellites and Space Probes Satellites orbit Earth, thousands are in orbit today Space Probes travel out in space and send back information about planets and moons Over 50 space probe missions have occurred in last 50 years. Sputnik- 1957, 1st satellite by Russians, Started space race

37. US owns over 400 active satellites. About 900 total active satellites There are over 26,000 pieces of space junk (old satellites and space craft parts)

38. Famous Space Probes Viking Mars Rovers Mariner Cassini Magellan Pioneer Voyager Galileo

39. Views from Mars Rovers “Spirit” and “Opportunity”

41. Manned Space Missions Project Mercury- 1958-63, One man spacecraft Goals orbit a manned spacecraft around Earth investigate man’s ability to function in space recover man and spacecraft successfully Alan Shepard- first American in space

43. Project Gemini- 1964-1966, Two man spacecraft Goals: test man and equipment for 2 week space flight dock with orbiting vehicles land on a pre-selected point

44. Project Apollo- 1968-1972, Three man spacecraft Goals: to achieve dominance in space to go to the moon develop man’s capability to work on the moon

46. Skylab-1973, Three manned space station Tested man’s ability to stay in space for extended periods

47. Space Shuttle- 1977-present, reusable space vehicle able to land like airplane

48. International Space Station-1998-present U.S. and Russian built.

49. Space program disasters Apollo 1- fire on launching pad, killed 3 astronauts Challenger- exploded 73 seconds after liftoff, killed 7 Columbia- broke apart upon re-entry, killed 7