Space Terms Flashcards
Orbit
The path of an object in space as it moves around another object due to gravity
Solar System
The Sun and its family of orbiting planets and moons and other objects.
Galaxy
Millions and 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 after a smaller object strikes the surface
Rotation
the act of rotating; a turning around as on an axis.
Revolution
The motion of one body around another, such as the Earth in its orbit around the Sun
Season
One of a pattern of temperature changes and other weather trends over the course of a year
Equinox
In an orbit, a position and time in which sun shines equally on both hemispheres.
Solstice
In an orbit, a position and time during which one hemisphere receives the maximum sunlight
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
the complete or perfect shadow of an opaque body, as a planet, where the direct light from the source of illumination is completely cut off.
Astronomical Unit (AU)
Average distance from the sun which is 93,000,000 miles
Ellipse
An oval or flattened circle.
Terrestrial Planet
A planet that has a rocky surface.
Gas Giant
A large planet that consists mostly of gases in a dense form
Asteroid
A small solid rocky body that orbits the Sun.
Comet
A body that produces a coma of gas and dust, a small icy body that orbits the Sun
Meteor
A brief streak of light produced by a particle entering Earths atmosphere at high speed.
Meteorite
A small object from outer space that passes through Earth’s atmosphere and reaches the surface.
Geocentric
Earth centered theory of the solar system.
Heliocentric
A Sun centered theory of the universe.
Gravity
The force that objects exert on one another because of their mass.
Tide
The rise and fall of the oceans caused by the gravitational pull of the moon and sun.
Waxing
The gradual increase of the illuminated surface of the moon.
Waning
The gradual decrease in the illuminated surface of the moon.
Gibbous Moon
More than half but less than fully illuminated
Crescent Moon
The illuminated surface is less than a quarter illuminated.
Full Moon
The entire surface of the moon is illuminated.
New Moon
The entire surface of the moon is not illuminated.
Quarter Moon
Half of the moon is illuminated.
Perihelion
the point in the orbit of a planet or comet at which it is nearest to the sun.
Aphelion
the point in the orbit of a planet or a comet at which it is farthest from the sun.
Axis of rotation
An imaginary line about which a turning body such as Earth rotates
