Solar System Flashcards
Orbit
The circular path of an object as it revolves around another object
Solar System
A system of objects that revolve around a star
Galaxy
a group of solar systems, dust, and gas held together by gravity; our solar system is part of the Milky Way galaxy
Universe
everything that exists in, on and around the Earth
Satellite
a natural or artificial object that revolves around another object in space
Impact Crater
a large, circular pit in the surface of a planet or other body in space usually formed when two bodies in space collide
Rotation
the spinning of a celestial body, such as a planet, around an axis
Revolution
The motion of one body around another, such as the Earth in its orbit around the Sun.
Season
One 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
are large, dark, basaltic plains on Earth’s Moon, formed by ancient volcanic eruptions.
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 partial or imperfect shadow outside the complete shadow of an opaque body, as a planet, where the light from the source of illumination is only partly 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 with 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 celestial body moving about the sun, usually in a highly eccentric orbit, consisting of a central mass surrounded by an envelope of dust and gas that may form a tail that streams away from the sun.
Meteor
A brief streak of light produced by a particle entering Earths atmosphere at high speed
Meteorite
a mass of stone or metal that has reached the earth from outer space; a fallen meteoroid.
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 ocean’s surface levels due to the gravitational pull of the sun and moon (related word: tidal)
Waxing
A gradual increasing of the Illuminated surface of the moon
Wanning
The gradual decrease in the illuminated surface of the moon
Gibbous Moon
More than half but less that 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
