click below
click below
Normal Size Small Size show me how
Earth, Moon, and Sun
Chapter 15, Sections 1-3 Vocabulary
Term | Definition |
---|---|
astronomy | the study of the moon, stars, and other objects in space |
axis | an imaginary line that passes through Earth’s center and the North and South poles, about which Earth rotates |
rotation | the spinning motion of a planet on its axis |
revolution | the movement of an object around another object |
orbit | the path of an object as it revolves around another object in space |
solstice | the two days of the year on which the sun reaches its greatest distance north or south of the equator: the summer solstice is the longest day of the year while the winter solstice is the shortest day of the year |
equinox | the two days of the year on which neither hemisphere is tilted toward or away from the sun |
force | a push or pull exerted on an object |
gravity | a force that pulls objects toward each other |
law of universal gravitation | the scientific law that states that eery object in the universe attracts every other object |
mass | the amount of matter in an object |
weight | the force of gravity on an object |
inertia | the tendency of an object to resist a change in motion |
Newton's first law of motion | the scientific law that states that an object at rest will stay at rest and an object in motion will stay in motion with a constant speed and direction unless acted on by a force |
phase | one of the different apparent shapes of the moon as seen from Earth |
eclipse | the partial of total blocking of one object in space by another |
solar eclipse | the blocking of sunlight to Earth that occurs when the moon is directly between the sun and Earth |
umbra | the darkest part of a shadow |
penumbra | the part of a shadow surrounding the darkest part |
lunar eclipse | the blocking of sunlight to the moon that occurs when Earth is directly between the sun and the moon |
tide | the daily rise and fall of Earth’s waters on its coastlines |
spring tide | a tide with the greatest difference between high and low tide that occurs when the sun and moon are aligned with Earth |
neap tide | a tide with the least difference between low and high tide that occurs when the sun and moon pull at right angles to each other |