Vocab Flashcards
Solar system
The sun and its family of orbiting planets, moons and other objects.
Galaxy
Millions or billions of stars held together in a group by their own gravity.
Universe
Space and all the matter and energy in it.
Satellite
An object that orbits a more massive object.
Impact crater
A round pit left behind on the surface of a planet or other body in space after a smaller object strikes the surface.
Axis of rotation
An imaginary line about which a turning body, such as Earth rotates.
Revolution
The motion of one body around each other, such as Earth in its orbit around the sun.
Season
One part of a pattern of temperature changes and other weather trends over the course of the year.
Equinox
In an orbit, a position in time in which the sunlight shines equally on the Northern Hemisphere and the Southern Hemisphere.
Solstice
In an orbit, a position and time during which one hemisphere gets its maximum amount of sunlight, while the other hemisphere gets its least amount.
Mare
A large, dark plain of solidified lava on the moon.
Eclipse
An event during which one object in space casts a shadow onto another.
Umbra
The dark, central region of a shadow, such as the cone of complete shadow cast by an object.
Penumbra
A region of lighter shadow that may surround an umbra.
Astronomical Unit
Earths average distance from the sun, which is approximately 150 million kilometers.
Ellipse
An oval or flattened circle.
Terrestrial planet
Earth or a planet similar to earth that has a rocky surface.
Gas giant
A large planet that consists mostly of gases in an dense form.
Asteroid
A small, solid, rocky body that orbits the sun.
Comet
A body that produces a coma of gas and dust.
Meteor
A brief streak of light produced by a small particle entering Earth’s atmosphere at high speeds
Meteorite
A small object from outer space that passes through Earth’s atmosphere and reaches the surface.
Geocentric
Having or representing the earth as a center, as in former astronomical systems.
Heliocentric
Having or representing the sun as a center, as in the accepted astronomical model of the solar system.