Earth's Motions

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axis
The imaginary vertical line that cuts through the center of Earth and around which Earth spins
ellipse
An elongated circle, or oval shape, the shape of the planets orbit.
hemisphere
Half of the earth usually referred to as eastern or western; northern or southern
revolution
Earth's yearlong elliptical orbit around the sun
rotation
Spinning of Earth on its imaginary axis, which takes about 24 hours to complete and causes day and night to occur
equinox
Twice-yearly time each spring and fall when the Sun is directly over the equator and the number of daylight and nighttime hours are equal worldwide
equator
An imaginary circle around the middle of the earth, halfway between the North Pole and the South Pole
latitude
The numbering system used to indicate the location of parallels drawn on a globe and measuring distance north and south of the equator
longitude
The numbering system used to indicate the location of meridians drawn on a globe and measuring distance east and west of the prime meridian (0°).
orbit
The path an object follows as it revolves around another object
crater
a bowl-shaped depression formed by the impact of a meteorite
maria
dark-colored, relatively flat regions of the Moon formed when ancient lava reached the surface and filled craters on the moon's surface
highlands
tall mountain ranges and appear as light areas on the moon
meteorite
a meteoroid that strikes the surface of a moon or planet
nuclear fusion
a nuclear reaction in which nuclei combine to form more massive nuclei with the simultaneous release of energy
23.5 degrees
the earth's tilt
waxing
(of the moon) pertaining to the period during which the visible surface of the moon increases
waning
(of the moon) pertaining to the period during which the visible surface of the moon decreases
gibbous
(used of the moon) more than half full
full moon
phase that occurs when all of the Moon's surface facing Earth reflects light
Copernicus
Polish astronomer who produced a workable model of the solar system with the sun in the center (1473-1543)
Galileo
Italian astronomer and mathematician who was the first to use a telescope to study the moon and stars
spring tide
highest tidal range that occurs to the alignment of Earth, the moon, and the sun
neap tide
a tide with the least difference between high and low tide that occurs when the sun and moon pull at right angles to each other
lunar eclipse
the earth interrupts light shining on the moon
solar eclipse
the moon interrupts light from the sun