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6 Sci Test 8 Ch 4B
Question | Answer |
---|---|
orbit | to revolve around |
ellipse | a symmetrically shaped oval |
foci | the two special points in an ellipse |
astronomical unit | the distance between the earth and the sun; equal to 93 million miles |
gravity | the force of attraction that exists between any two objects |
planets | the largest heavenly bodies that orbit the sun |
solar system | the sun and all the heavenly bodies that orbit it |
solar year | the time required for the earth to complete one revolution around the sun; equal to 365 1/4 days |
atmosphere | the blanket of air that makes the earth hospitable for living things |
ozone layer | a region of the atmosphere, located between 10 and 30 miles above the earth's surface, that filters out most of the harmful ultraviolet radiation from the sun |
greenhouse effect | the ability of the earth's atmosphere to retain heat around the earth |
maria | "seas"; large, dark-colored plains on the surface of the moon |
lunar month | the time it takes for the moon to complete a full cycle in its orbit around the earth |
near-earth asteroids | a group of asteroids located in the inner solar system, many of which cross paths with the earth |
period | the time it takes for a comet to complete an orbit around the sun |
Kepler | he discovered the planets do not travel in perfect circles, but in ellipses; formulated three laws of planetary motion |
Copernicus | he presented the idea that all the planets orbit the sun, and that the earth itself is also a planet |
Newton | he discovered the law of universal gravitation |
Ptolemy | he presented the idea of an earth-centered universe |
My very excited mother just served us noodles | planets in order; Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune |
nucleus, coma, tail | parts of a comet |
revolution | a single trip around the sun ( or other heavenly body) |
rotation | the spinning of the earth (or other object) |
spring tide | an especially high or low ocean tide that occurs during a new moon or a full moon, when the sun and moon are in line with the earth and their gravitational forces are working together |
neap tide | a weaker ocean tide that occurs during a first-quarter moon and a third-quarter moon, when the gravitational forces of the sun and moon work at right angles against each other |
solar eclipse | occurs when the earth's moon passes in front of the sun, blocking the sun's light |
lunar eclipse | occurs when the moon passes through the earth's shadow, causing the moon to appear darkened |
asteroid | a small, rocky object that orbits the sun |
comet | an asteroid-sized object that develops a huge, bright tail when it domes near the sun |
asteroid belt | a region between Mars and Jupiter where most asteroids are located |
Kuiper belt | a region farther from the sun than the planet Neptune where a large number of objects resembling comet nuclei are located |
meteoroid | piece of space debris that is smaller than the smallest asteroids |
meteor | space particle traveling within the earth's atmosphere |
meteorite | a meteor that has landed on the earth's surface |
first law of planetary motion | every planet orbits the sun in an ellipse, with the sun as one of the foci of the ellipse and an empty point in space as the other |
second law of planetary motion | as a planet moves closer to the sun, it travels faster; and as it moves farther away, it slows down |
third law of planetary motion | shows the relationship between a planet's distance from the sun and the time it takes the planet to complete one orbit |
new moon | the beginning of the lunar month when the sunlit side of the moon is turned away from Earth and completely hidden from view |
first-quarter moon | the phase of the visible moon when it is half light and half dark |
crescent phase | the stage of the visible moon when it waxes from the new moon to the first-quarter moon and wanes from third-quarter to the new moon |
full moon | the phase of the moon when we see the entire sunlit side |
gibbous phase | the term for the visible moon when it seems to bulge as it waxes from first quarter to full and wanes from full to third quarter |
third-quarter moon | the stage of the visible moon when it is half dark and half light again |
waxes | to grow larger, as the moon seems to as it goes through it phases |
wanes | to shrink, as the moon seems to as it goes through it phases |