click below
click below
Normal Size Small Size show me how
Space Set 1
Key Vocabulary for Space Systems Lessons 1 and 2
Term | Definition |
---|---|
Satellite | An object that orbits a planet; any object that orbits around another object in space. |
Star | A ball of hot gas, primarily hydrogen and helium, that undergoes nuclear fusion. |
Planet | An object that orbits a star, is large enough to have become rounded by its own gravity, and has cleared the area of its orbit. |
Comet | A loose collection of ice and dust that orbits the sun, typically in a long, narrow orbit. |
Constellation | A pattern or grouping of stars that suggest the outline of a figure or object. |
Geocentric | Term describing a model of the universe in which Earth is at the center of the revolving planets and stars. |
Heliocentric | Term describing a model of the solar system in which Earth and the other planets revolve around the sun. |
Ellipse | An oval shape, which may be elongated or nearly circular; the shape of the other planets' orbits. |
Axis | An imaginary line that passes through a planets' center and its north and south poles, about which the planet rotates. |
Rotation | The spinning motion of a planet on its axis (results in day/night). |
Revolution | The movement of an object around another object (results in a planet's year as it goes around the sun). |
Orbit | The path of an object as it revolves around another object in space. |
Solstice | Either of the two days of the year on which the sun reaches its greatest distance from the equator (Summer Solstice and Winter Solstice). |
Equinox | Either of the two days of the year on which neither hemisphere is tilted toward or away from the sun. |
Gravity | The attractive force between objects; the force that moves objects downhill. |
Law of Gravitation | The scientific law that states every object in the universe attracts every other object. |
Inertia | The tendency of an object to resist change in motion. |