ASTR 111 Study Guide

  1. Introduction
  2. History of astronomy
  3. Navigating the sky
  4. The sky, star motions, calendars, etc.
  5. The seasons, phases of the Moon
  6. Eclipses
  7. The Solar System
  8. Earth
  9. Moon
  10. Mercury
  11. Venus
  12. Mars
  13. Jupiter
  14. Saturn, Uranus, Neptune
  15. Pluto & other Solar System objects

Introduction & Background Material

  • What is the difference between the solar system, galaxy, and universe?
  • What is a light year (ly)?
  • Define an astronomical unit (AU).
  • Place in order of increasing size: parsec, AU, ly
  • Did the solar system form as a direct result of the Big Bang?
  • List the planets, in order, from closest to the Sun outward.

History of Astronomy

  • What is retrograde motion? Why was it important?
  • Detail the evolution from the geocentric to heliocentric model for our solar system.
  • What contribution(s) did Ptolemy, Copernicus, Kepler and Newton make?

Navigating the Sky

  • Discuss how to recognize the Big Dipper, and use it to find 2 other stellar objects.
  • What makes Polaris special?
  • What does Cassiopeia really look like?
  • List the major stars in the Summer Triangle.
  • Describe how to find the Andromeda Galaxy.
  • What does Bootes look like? What is its major star?

The Sky, Star Motions, Coordinates, and Calendars

  • Explain how constellations differ from asterisms.
  • Define/explain: Celestial Sphere, NCP, SCP, celestial equator, ecliptic, equinoxes, solstices
  • Be able to label all of the important points on the Celestial Sphere.
  • What effect does Earth’s rotation have on the motion of stars in the sky?
  • How does your location on Earth affect what you see in the sky?
  • Define/explain: Arctic & Antarctic Circles, Tropics of Cancer & Capricorn
  • Know where the Sun is (as seen from Earth) on solstices & equinoxes.
  • What is precession? How has it affect our view of the sky?

Seasons and Phases of the Moon

  • What causes seasons on the Earth? What common answer is incorrect?
  • Give 2 reasons why are summers warmer than winters in the northern hemisphere.
  • Know the order of the phases of the Moon; be able to draw them, give rise/set times.
  • Explain the difference between synodic and sidereal periods of the Moon.


  • List 2 conditions required for an eclipse.
  • Define umbra and penumbra.
  • Be able to discuss the three types of lunar eclipses in detail.
  • Be able to discuss the three types of solar eclipses in detail.
  • Why does the Moon appear red during a total lunar eclipse?
  • Why are eclipses so rare?
  • Why are solar eclipses so short compared to lunar eclipses?

Solar System

  • What is a nebula? A solar nebula?
  • Why are the terrestrial (rocky) planets closer to the Sun?
  • Be able to describe the time-line of planetary formation: planetesimals to planets.
  • How did the way planets form affect things like the shape of orbits & the ecliptic?
  • What are comets and asteroids?
  • How do we know how old the solar system is?


  • What is the Earth’s interior like? How do we know?  Detail its layers/make up.
  • What is Plate Tectonics?  What evidence is there for it?
  • How did Earth’s atmosphere originally form? How did it change over time? Why?
  • List the various kinds of radiation in the EM spectrum.
  • What kinds of radiation reach Earth’s surface?
  • Why do aurora form?


  • List major surface features on the Moon.
  • What is regolith? How does it differ from soil?
  • Describe the various formation theories for the Moon.
  • What is synchronous rotation?
  • Why do we have tides on the Earth?  What is their impact?
  • Define spring and neap tides.


  • How does Mercury differ from the Moon?
  • Name surface features on Mercury that were discussed in class.
  • Why does Mercury have such a weak magnetic field?


  • Why is Venus so hot?
  • Compare the atmospheres, past and present, of Earth and Venus.
  • Why are there so few craters on Venus?
  • Why do we have so few pictures of the surface of Venus?


  • What are the Martian “canals”?
  • Discuss a few of the major surface features on Mars.
  • Compare Mars’ atmosphere to that of Earth.
  • Did Mars ever have flowing water? What evidence is there?
  • What happened to the water on Mars?
  • Does Mars have moons? If so, how many & describe their origin.

Jupiter & Saturn

  • How big is Jupiter? What is it made of?
  • What are belts and zones?
  • What is the Great Red Spot, and why has it survived so long?
  • Name all 4 Galilean moons and a few interesting facts about each.
  • What forms the rings around Saturn?
  • What other planets also have rings?
  • Why is Saturn’s atmosphere less stormy than Jupiter’s?
  • What is interesting about Saturn’s moon Titan?

Uranus, Neptune & Pluto

  • What strange feature does Uranus have compared to the other planets?
  • What gives Neptune its distinctive colour?
  • Compare the outer planets to each other.
  • What is unusual about Pluto? What is Charon?

Other Solar System objects

  • How do asteroids, comets and meteors compare to each other? Differ?
  • What is the difference between meteoroids, meteors, and meteorites?
  • What are the 3 main parts of a comet?
  • Why do comets have tails?
  • What happened to the dinosaurs?