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32 Cards in this Set
- Front
- Back
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lunar gravitational attraction |
low mass relative to Earth, one-sixth that of Earth |
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Why does Earth only have one satellite,while Jovian planets have a lot? |
large size = greater gravity = more particles attracted |
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How did the moon form? |
collision between a Mars-sized body and young Earth |
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Moon’s low density and internalstructure |
large mantle and asmall iron-rich core |
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Lunar Surface |
two different types of terrain:dark lowlands and brighter,highly cratered highlands |
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maria(mar = sea, singular mare) |
dark regions appeared smooth (resembling seas on Earth) |
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terrae (Latin for “land”) / lunar highlands |
light-colored areas resemble Earth’s continents |
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Lunar Regolith |
rhegos = blanket, lithos = stone mantled both the maria and terrae gray debris
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Why are impact craters on the moon very evident compared to Earth? |
no atmosphere and water = no weathering and erosion erosion > bombardment of micrometeorites, somehow smoothens the surface |
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Lunar Motions |
29 ½ days (synodic month) 27 1/3 days (sidereal month) in synchronous rotation with Earth (always showing the same face) |
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Synchronous Rotation |
period of rotation on its axis equals its period of revolution around Earth |
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Phases of the Moon |
Crescent, Third Quarter, Gibbous, Full Moon |
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Perigee |
when the moon is closest to Earth |
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Apogee |
when the moon is farthest away from Earth |
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Super Moon |
a full moon coincides with being closest to Earth happens once or twice a year |
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Micro Moon |
a full moon that occurs when the moon is farthest from Earth |
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Blue Moon |
the second full moon in a calendar month the first of the full moons must appear at or near the beginning of the month so that the second will fall within the same month
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Eclipse (eclipsis = failure to appear) |
occurs when one heavenly body blocks the light shining from a second onto a third |
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Solar Eclipse |
occur only during new moonphase when the Moon moves in aline directly between Earth and the Sun, it casts a darkshadow on Earth
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Umbra |
total solar eclipses are visibleonly to people in the dark part of the Moon’s shadow |
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Penumbra |
partial eclipse is seen by those in the light portion |
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Lunar Eclipse |
occur only during full moon phase the Moon is eclipsed when it moves within Earth’s shadow Earth’s circular shadow moves slowly acrossthe disk of the full Moon |
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Tides |
periodic rises and falls of large bodies of water caused by thegravitational interaction between the Earth and the Moon |
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Diurnal tidal pattern |
characterized by a single high tide and a single low tide eachtidal day |
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Semidiurnal tidal pattern |
exhibits two high tides and two low tides each tidal day, withthe two highs about the same height and the two lows aboutthe same height |
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Mixed tidal pattern |
- similar to a semidiurnal pattern except that it is characterizedby a large inequality in high water heights, low water heights,or both - there are usually two high and two low tides each day, withhigh tides of different heights and low tides of different heights |
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Spring Tides |
strong tides occur when the Earth,the Sun and the Moon arein a line (syzygy) gravitational forces of theMoon and the Sun bothcontribute to the tides |
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Proxigean Spring Tide |
very high tide occurs when the moon is both unusually at its perigee in the New Moon phase |
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Neap Tides |
weak tides occur when the gravitational forces of the Moon and the Sunare perpendicular to one another (with respect to the Earth) pulling in different directions giving minimum effect, occur during quarter moon
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Soviet Union - Luna Program |
Luna 1 - first man-made object toescape Earth's gravity and passnear the Moon Luna 10 - first unmanned vehicle toorbit the Moon |
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Apollo Program - USA |
Apollo 8 - first crewed mission to orbit the moon Apollo 11 - landing of the first humans on the Moon |
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Why do we sometimes see theMoon in the daytime? |
It will be visible inthe morning (AM side of the Earth) starting at full moon,during third quarter until a few days before new moon |
