rotation
The spinning of the Earth on its axis. Causes day and night.
axis
the imaginary line that passes through Earth's center and the north and south poles
revolution
the movement of one object around another. Earth revolves around the sun, & the Moon revolves around the Earth
orbit
the path followed during revolution
equinox
neither hemisphere is tilted toward or away from the sun. Occurs in March & September, 12 equal hours of day and night
solstice
when Sun is farthest north or south of the Equator, axis is tiled toward or away from the sun. Occurs in December & June.
Sir Isaac Newton
scientist who stated the Laws of Motion
gravity
the force that attracts all objects towards each other
inertia
the tendency of an object to resist a change in motion
weight
measurement of the force of gravity of an object, this can change with location
crater
large, round pits on the moon caused by the impact of meteoroids and chunks of rock or dust from space
maria
dark flat areas on the moon formed from ancient lava flows
solar eclipse
The blocking of sunlight to Earth that occurs when the moon passes directly between the sun and the Earth
lunar eclipse
The blocking of sunlight to the moon that occurs when the Earth is directly between the sun and the moon
phase
One of the different apparent shapes of the moon as seen from Earth.
geocentric
Earth centered. Theory that Earth is the center of the universe.
heliocentric
Sun centered. Theory that the Sun is the center of the universe.
moon
A natural satellite that revolves around a planet.
terrestrial planet
The name often given to the four inner planets: Mercury, Venus, Earth, and Mars
gas giant
The name often given to the first four outer planets: Jupiter, Saturn, Uranus, and Neptune
comet
A loose collection of ice, dust, and small rocky particles, typically with a long, narrow orbit of the sun
asteroid
Rocky objects revolving around the that are too numerous and small to be considered planets.
meteoroid
A chunk of rock or dust in space
meteorite
A meteoroid that passes through the atmosphere and hits Earth's surface.
meteor
A streak of light in the sky produced by the burning of a meteoroid in the atmosphere.
asteroid belt
The region of the solar system between the orbits of Mars and Jupiter, where many asteroids are found.
Kuiper belt
A doughnut-shaped region that stretches from around Plauto's orbit to about times Earth's distance from the sun.
Oort cloud
a spherical region of comets that surrounds the solar system.