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Crash Course Astronomy: Distances (11:20)

Key Ideas

As this video progresses, key ideas will be introduced to invoke discussion.

Key Ideas

Think about the following questions as you watch the video

  1. 01:58 What enabled Eratosthenes to calculate the different kinds of shadows the Sun cast at noon during the summer solstice?
  2. 02:55 What distances does knowing the Earth’s circumference help us calculate?
  3. 03:57 What distance is the astronomical unit based upon?
  4. 04:54 Why did scientists use radio telescopes to bounce radar pulses off of Venus?
  5. 06:16 What does having two eyes enable us to do, regarding distances?
  6. 07:05 What does the Earth’s orbit have to do with calculating distances to stars?
  7. 08:46 Why do we use measurements like light-years and parsecs?
  8. 09:46 What does spectroscopy—measuring the brightness of a star—have to do with distance?