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39 Cards in this Set
- Front
- Back
law of universal gravitation |
every object in the universe attracts every other object, depending on their masses and distances from one another |
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solstice |
the two days of the year in which the sun's most direct rays reach farthest north or farthest south |
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equinox |
the two days of the year when day and night are almost the same length everywhere on earth |
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crescent |
the moon phase in which less than half of the moon's sunlit side is visible |
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gibbous |
the moon phase in which more than half, but not all, of the moon's sunlit side is visible |
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wax |
to grow |
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wane |
to shrink |
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lunar eclipse |
an event that occurs when Earth passes directly between the sun and the moon, causing Earth's shadow to block the sun's light from the moon |
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solar eclipse |
an event that occurs when the moon passes directly between the sunned Earth causing the moon's shade to block the sun's light from a portion of Earth |
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tide |
the periodic rising and falling of the surface level of ocean water |
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spring tide |
a condition of the greatest difference between low and high tides |
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neap tide |
a condition of the least difference between low and high tides |
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mare |
a dark, flat area on the moon's surface filled with hardened lava |
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Crater |
A large round depression that has been created by the impact of a meteoroid |
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Newton's First Law of Motion |
The tendency for an object to stay in motion or to stay at rest unless acted upon by an outside force |
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Orbit |
The path of an object as it revolves around another object |
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Meteoroid |
A small rock fragment from an asteroid or comet |
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Weight |
A measure of the pull of gravity on an object |
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Mass |
The measure of how much matter is within an object. It affects gravitational pull |
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Gravity and inertia |
Two factors that affect the moon's orbit around the Earth |
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Gravity, Inertia, Mass, Distance |
Four factors that influence the motions of the early and moon. |
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axis |
An imaginary line that the earth spins on |
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Earth Rotation |
The earth takes one day to rotate one time |
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365 1/4 |
The number of days the Earth takes to make one revolution |
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1/6 |
The moon's gravity is about 1/6 of the Earths gravity since it has a smaller mass |
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Equinox |
Occurs when neither of the Earth's poles is close to the sun. |
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March 21 |
Spring Equinox |
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September 22 |
Fall Equinox |
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Solstice |
Takes place due to the maximum tilt of the Earth's axis toward and then away from the sun. |
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June 22 |
Summer Solstice |
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December 22 |
Winter Solstice |
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Seasons |
Determined by the Earth's tilted axis as it revolves around the sun |
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Solar Eclipse |
Can only occur during a new moon because the moon is directly between the sun and the earth. |
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Lunar Eclipse |
Only happens during a full moon because the earth is directly between the sun and the moon |
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Sun's Shadow |
Results from the Earth's position compared to the sun's location in the sky |
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Partial or Total Eclipse |
Dependent upon whether the sound, earth, moon are directly lined up |
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Craters, maria, highlands |
Features of the moon |
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Moon visibility |
Only one side of the moon can be observed from Earth. The rotation of the moon and the earth cause only the near side of the moon to be seen. It can be seen during the day or night d spending on the phase it is in, the weather, and the time |
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Neil Armstrong |
The first person to walk on the moon |