The Solar System

Practice exam questions written by Timothy H. Heaton,
Professor of Earth Sciences, University of South Dakota

Click the circle by an answer with the mouse, then click on the Submit button to get a response. You will be told if your answer is correct or not and will be given some comments.

  1. What two elements is the universe made primarily of?
    Carbon and nitrogen
    Hydrogen and helium
    Iron and nickel
    Silicon and oxygen

  2. What is the correct order of the planets in the Solar System, starting closest to the Sun?
    Mars, Mercury, Earth, Venus, Jupiter, Saturn, Uranus, Neptune, Pluto
    Mercury, Mars, Earth, Venus, Jupiter, Saturn, Uranus, Neptune, Pluto
    Mercury, Mars, Venus, Earth, Jupiter, Saturn, Uranus, Neptune, Pluto
    Mercury, Venus, Earth, Mars, Jupiter, Neptune, Uranus, Saturn, Pluto
    Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto

  3. What is thought to be the age of the nine planets relative to each other?
    The inner planets formed together first and then the outer planets formed together later
    The outer planets formed together first and then the inner planets formed together later
    They all formed at roughly the same time
    They formed sequentially from Pluto inward with the one nearest the sun formed last
    They formed sequentially from the sun outward with Pluto formed last

  4. Why does the moon have more craters than the earth?
    Craters develop much better on smaller planetary bodies
    The moon captured most asteroids before they could strike the earth
    The moon has a stronger gravitational attraction than the earth
    The moon has little tectonics or weathering to obliterate craters
    The moon is much older than the earth

  5. What elements are the atmospheres of Jupiter and Saturn primarily composed of?
    Argon and krypton
    Hydrogen and helium
    Nitrogen and carbon dioxide
    Nitrogen and methane
    Nitrogen and oxygen

  6. Where did the heavy elements that make up the bulk of the earth originate?
    In a supernova
    In meteorites
    In the Big Bang
    In the earth itself
    In the sun

  7. What are the lunar maria made of?
    Basalt
    Breccia
    Granite
    Salt
    Water

  8. Which planet is closest in size to the earth?
    Mars
    Mercury
    Neptune
    Uranus
    Venus

  9. Which planet besides the earth has evidence of erosion by running water?
    Mars
    Mercury
    Neptune
    Uranus
    Venus

  10. Which planet has a runaway greenhouse effect?
    Mars
    Mercury
    Neptune
    Uranus
    Venus

  11. Which planet has virtually no atmosphere?
    Mars
    Mercury
    Neptune
    Uranus
    Venus

  12. What is the largest planet in the solar system?
    Earth
    Jupiter
    Mars
    Neptune
    Saturn

  13. Which of the following planets is not a gas giant?
    Jupiter
    Neptune
    Pluto
    Saturn
    Uranus

  14. Which planet has the most extensive ring structure?
    Jupiter
    Neptune
    Pluto
    Saturn
    Uranus

  15. What is Io?
    A comet
    A moon of Jupiter
    A protoplanet
    An asteroid
    The nearest star

  16. What speed is needed for a gas molecule to escape from a planet?
    Escape velocity
    Orbital speed
    Solar wind speed
    Speed of light
    Speed of sound

  17. What are comets mostly made of?
    Ammonia
    Hydrogen
    Ice
    Iron
    Rock

  18. What is the glowing head of a comet called?
    Coma
    Crater
    Head
    Maria
    Nova

Please report any problems or errors to Dr. Heaton.