Astronomy HW#02: Motions of the Moon and the Copernican Revolution

  1. What is true of the Moon's orbital and rotational periods?





    C.
  2. What was the greatest contribution of Tycho Brahe to astronomy?





    • B.
    • Kepler later used this wealth of data to confirm the Copernican model.
  3. How did Ptolemy's model explain the retrograde motions of the planets?




    • B.
    • This is the explanation Ptolemy gave, although it was not supported by modern observations.
  4. True or False:

    A planet (or comet) will speed up as it approaches the Sun.
    True
  5. What will occur when the full moon is on the ecliptic?




    B.
  6. Suppose that instead of being inclined to Earth's orbit around the Sun, the Moon’s orbit was in the same plane as Earth’s orbit around the Sun. In this hypothetical situation, approximately how many solar eclipses would occur each year?




    A.

    If the Moon orbited Earth in the same plane that Earth orbits the Sun (the ecliptic plane), we would have a solar eclipse at every new moon. Because there are about twelve new moons in a year, we would have twelve solar eclipses. Of course, this isn’t what really happens.
  7. In reality, the Moon’s orbit about Earth is tilted (by about 5°) with respect to Earth’s orbit about the Sun. As a result, the actual number of solar eclipses that occur each year is approximately _____.




    A.

    There are generally two periods of time each year when eclipses are possible — the “eclipse seasons” — and there is a solar eclipse of some type (partial, total, or annular) during each of these eclipse seasons. (Because the time between eclipse seasons is less than six months, in some years there is a third eclipse season and hence a third solar eclipse.)
  8. What conditions must exist for a solar eclipse to occur?




    B.

    The two points at which the Moon’s orbit crosses the Earth’s orbital plane are called the nodes of the Moon’s orbit. So another way to state the conditions for a solar eclipse is that (1) it must be new moon, and (2) the Moon must be at or quite near one of the nodes of its orbit.
  9. What conditions must exist for a lunar eclipse to occur?




    C.

    The two points at which the Moon’s orbit crosses the Earth’s orbital plane are called the nodes of the Moon’s orbit. So another way to state the conditions for a lunar eclipse is that (1) it must be full moon, and (2) the Moon must be at or quite near one of the nodes of its orbit.
  10. If you could change the layout of the solar system, which of the following would cause a lunar eclipse to occur at least once every month in this hypothetical situation?




    D.

    the Moon’s orbit has to be in line with Earth’s orbit in order for a lunar eclipse to happen just about every month.
  11. According to Newton, planets orbit in ellipses with what at the two foci?




    B.

    Newton recognized that two orbiting bodies orbit in ellipses with their common center of mass at one focus and nothing at the other focus.
  12. How did Copernicus' model explain the retrograde motions of the planets?



    D.

    This was indeed Copernicus' explanation. It was much simpler than Ptolemy's!
  13. Which of these was NOT seen telescopically by Galileo?





    D.
  14. The smallest high tides occur when the Moon phase is





    B.
  15. If the Moon appears half lit, and is almost overhead about 6:00 AM, its phase is





    D.
  16. True or false:

    From full moon to third quarter moon takes about a week.
    True
  17. A solar eclipse can only happen during a





    B.
  18. Kepler's first law worked, where Copernicus' original heliocentric model failed, because Kepler described the orbits as





    D.
  19. The interval from new Moon to first quarter is about a(n)





    D.
  20. The Moon's near side always faces Earth due to





    C.
  21. Galileo's observations of the phases of Venus ________.




    B.
  22. Galileo found the rotation period of the Sun was approximately





    A.
  23. True or false:

    Eighteen days past new moon, the Moon's phase is waning gibbous.
    True
  24. 1.) Earth is located at one ______ of the Moon's orbit.

    2.) According to Kepler's second law, Jupiter will be traveling most slowly around the Sun when at ________.

    3.) Earth orbits in the shape of a/an ________ around the Sun.

    4.) The mathematical form of Kepler's third law measures the period in years and the _________ in astronomical units (AU).

    5.) According to Kepler's second law, Pluto will be traveling fastest around the Sun when at ________.

    6.) The extent to which Mars' orbit differs from a perfect circle is called its _______.

    Choices: Ellipse
    Aphelion
    Perihelion
    Focus
    Semimajor Axis
    Eccentricity
    • Focus
    • Aphelion
    • Ellipse
    • Semimajor Axis
    • Perihelion
    • Eccentricity
  25. True or false:

    A planet (or comet) will speed up as it approaches the Sun
    True
  26. The force of gravity varies with





    E.
  27. In an annular eclipse,





    E.
  28. According to Copernicus, retrograde motion for Venus must occur around





    B.
  29. Copernicus proposed a heliocentric model for the solar system primarily because ________.




    D.
  30. True or false:

    According to Kepler's third law, if you know the planet's orbital period, you can find its average distance from the Sun.
    True
  31. True or false:

    Copernicus believed the Earth was the center of all celestial motion.
    False
  32. How much stronger is the gravitational pull of the Sun on Earth, at 1 AU, than it is on Saturn at 10 AU?





    C.
  33. The place in a planet's orbit that is closest to the Sun is called





    C.
  34. Which of the following was NOT one of the discoveries made by Galileo?




    A.

    This discovery was made by Kepler.
  35. If the distance between two asteroids is doubled, the gravitational force they exert on each other will





    D.
  36. An Astronomical Unit (AU) is _________.





    D.
  37. In what way did Newton improve Kepler's laws?




    D.
Author
SeanHatfield
ID
314986
Card Set
Astronomy HW#02: Motions of the Moon and the Copernican Revolution
Description
Astronomy Homework 02. Motions of the Moon and the Copernican Revolution. Dr. Wallin. Sean Hatfield
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