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Chp. 19 Space
(Science)
Question | Answer |
---|---|
Rotation | the spinning of the Earth on its axis; causes day and night; takes 24 hours to rotate once |
Revolution | one complete orbit of Earth around the sun; one year |
Orbit | the path the Earth follows around the sun and the moon around the Earth. It is elliptical shaped. |
Seasons | result because the tilt of the Earth as it orbits the sun |
Solstices | when the sun is farthest north or south of the equator |
Equinox | occurs when neither end of the Earth’s axis is tilted toward or away from the sun. Day and night are both 12 hours long (equal). |
Gravity | objects attracted to each other by force |
The strength of the force of gravity depends on two factors; | the masses of the objects and the distance between them. |
Inertia | the tendency of an object to resist change in motion |
Inertia and gravity | keep the Earth and moon in their orbits |
Solar Eclipse | sun/moon/earth |
Lunar Eclipse | sun/earth/moon |
Umbra | darkest part of a shadow |
Penumbra | part of a shadow that is less dark |
Spring Tide | sun/moon/ earth in a straight line; causes the greatest difference between high and low tides |
Neap Tide | sun/earth/moon at a right angle; causes the least difference between high and low tides |
Craters | large round pits on the moon’s surface |
Maria | dark flat areas on the moon’s surface |
Highlands | light colored features on the moon’s surface (mountains) |
Moon’s Size | about one fourth the Earth’s diameter |
Moon’s Temperature | varies from night and day because there is no atmosphere |
Rocket | a device that expels gas in one direction to move in the opposite direction |
Thrust | the reaction force that propels a rocket forward |
Orbital Velocity | velocity a rocket must have to establish an orbit around Earth |
Escape Velocity | velocity a rocket must reach to fly beyond a plant’s gravitational pull |
Satellite | an object that /revolves/orbits around another object in space |
NASA | National Aeronautics and Space Administration est. 1958 |
Humans in Space: | Yuri Gargarin –Soviets first human in space, 1961 Alan Shepard- first American in space less than a month later John Glenn- first American to orbit Earth, 1962 |
The “Space Race” was between the United States and the | Soviet Union. It heated up when the Soviet Union launched Sputnik I. |
The American effort to land astronauts on the moon was called the | Apollo program. |
Space Shuttle | can be used many times to carry astronauts into orbit and can land like a plane |
Space Station | large artificial satellite on which people can live and work for long periods of time. |
Space Probes | a spacecraft that carries scientific instruments that can collect data but has no human crew |