Section 3 Space

• Telescopes


  • Showed us that earth is not the center of the universe
  • Revealed new planets, asteroids, & craters on the moon
  • Helped us understand laws of the physical world
  • Helped us understand that light radiates from stars
• Hans Lippershey's Telescope (known as the first telescope)


  • It had convex and concave lenses inside a tube and magnified objects 3-4x
  • To improve the quality of the telescope they would end up building very long telescopes, up to 60 feet
• Concave and convex lenses

  • Concave
  • Convex
• Optical Telescopes


  Contain Lenses
• Galileo was the first one to use the telescope for astronomy
• Refracting Telescope


  • Use 2 lenses to focus light from visible Stars
  • Can only be so large before lenses start to warp
• Reflecting Telescope


  • Use mirrors instead of lenses
  • One end of the telescope has a concave Mirror and a flat diagonal 2nd mirror
• Interferometry


  A technique of using telescopes in combination to detect objects with better clarity at greater distances
• Hubble Space Telescope


  • Positioned 326 miles (525km) above earth's surface
  • Provides a clear view of the universe without obstructions from clouds, pollution etc
  • Able to detect a large range of light
• Electromagnetic Spectrum


  The range of radiated/electromagnetic energy that travels at the speed of light, with different wavelengths and frequencies
• Examples of electromagnetic radiation

  • Gamma rays
  • X-rays
  • Ultraviolet
  • Visible light
  • Infrared
  • Microwaves
  • Radio waves
• Visible light spectrum is the wavelengths of light visible to the naked eye
• Stars, and galaxies emit more than just light, they also emit radio waves, infrared/heat waves, and X-rays
• Radio Telescopes


  • Receive and amplify radio waves that originate from the stars, planets, galaxies and other bodies to learn about their structure, motion and composition
  • Can operate day and night, not impacted by weather
  • Must be far away from other radio waves
• Space Probes


  • Observation equipment that are unmanned
  • Many probes measure properties of Space
  • Some have telescopes or other instruments
  • Better probes are often called orbiters, landers, and rovers
• Triangulation


  A process that allows us to determine the distance between two objects that we cannot reach/get to, e.g. determining distance to stars
• Parallax


  Astronomers use parallax to determine the angles needed for triangulating the stars' distance from Earth
• Doppler Effect


  Changes in waves can determine the change in pitch that one hears due to motion (compressed vs expanded wavelengths)
• Red Shift


  Stars that are red shifted show spectra that appear to have lower frequencies (spread out wavelengths), indicating they are moving away from Earth
• Blue Shift


  Stars that are blue shifted show spectra that appear to have higher frequencies (compressed wavelengths), indicating they are moving towards Earth
• Emission Spectrum


  Peaks and dips of specific points in the spectrum indicate the presence of elements
• Continuous Spectrum


  Spectrum with no gaps or dips
• Absorption Spectrum


  Spectrum with dark lines indicating the absorption of specific wavelengths
• Celestial bodies are natural objects such as planets, moons, stars, asteroids, comets, nebulae, galaxies, black holes, etc., which exist in outer space.