Space Vocabulary Science Test Flashcards
Solar system
The sun and its family of orbiting planets, moons, and other objects
Galaxy
A group of millions or billions of stars held together by their own gravity
Universe
Everything-space and all matter and energy in it
Satellite
An object that orbits a more massive object
Impact crater
A crater on a planet or the moon made by a meteorite or other object
Axis of rotation
An imaginary line running through the earths center
Revolution
The motion of one object around another
Season
Patterns of temperature changes and other weather trends over the course of a year
Equinox
Sunlight shines equally on the north and south hemispheres; when one half is lit the other is dark
Mare
The low-lying dark areas on the moon or other planets
Eclipse
The sun, moon, and earth line up exactly, a shadow crosses earth or the moon; in a lunar eclipse the moon darkens but in a solar eclipse the sun darkens
Orbit
The path of an object in space as it moves around another object because of gravity
Umbra
The darker shadow of earth
Penumbra
The lighter come shaped shadow of earth
Astronomical unit (AU)
About 150 kilometers; earth is about one AU from the sun
Ellipse
The shape of each orbit-a flattened circle or oval
Terrestrial planet
Mercury, Venus, earth, and the sun, being the four closest planets to the sun
Gas giant
Jupiter, Saturn, Uranus, and Neptune, being made mainly of hydrogen, helium, and other gases
Asteroid
Small solid rocky bodies that orbit close to the sun
Comet
An object that produces a coma
Meteors
Particles in the air hot enough to glow producing brief streaks of light
Meteorite
A space object that reaches earths surface
Geocentric
Having or representing the earth as a center
Heliocentric
Having or representing the sun as the center, as in the astronomical model of the solar system
