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science 5
orbit and outer space stuff
Term | Definition |
---|---|
solar eclipse | occurs when the moon passes directly between the sun and earth and casts a shadow over a part of the earth |
orbit | the path taken by an object revolving around another |
ellipse | elongated, closed curve that describes earth's year long orbit around the sun |
revolution | earth's year long elliptical orbit around the sun |
rotation | spinning of earth on its imaginary axis, which takes 24 hours to complete and causes day and night to occurs |
axis | imaginary vertical line that cut through the center of earth and around which earth spins |
sphere | a round, three-dimensional object whose surface is the same distance from its center at all points; earth is a sphere that bulges somewhat at the equator and is slightly flattened at the poles |
maria | dark-colored, relatively flat regions of the moon formed when ancient lava reached the surface and filled craters on the moon's surface |
lunar eclipse | occurs when earth's shadow falls on the moon |
solstice | twice-yearly point at which the sun reaches its greatest distance north or south of the equator |
equinox | twice-yearly time at each spring and fall when the sun is directly over the equator and the number of daylight and nighttime hours are equal worldwide |
moon phase | change in appearance of the moon as viewed from the earth, due to the relative positions of the moon, earth, and sun |
new moon | moon phase that occurs when the moon is between the earth and sun, at which point the moon cannot be seen because its lighted half is facing the sun and its dark side faces the earth |
waxing | describes phases following a new moon, as more of the moon's lighted side becomes visible |
full moon | phase that occurs when all the moon's surface facing earth reflects light |
waning | describes phases that occur after a full moon, as the visible lighted side of the moon grows smaller |