Space Flashcards
(34 cards)
Orbit
the circular path of an object as it revolves around another object
because of gravity.
Solar System
a system of objects that revolve around a star
Galaxy
a group of solar systems, dust, and gas held together by gravity
Universe
Space and all the matter and energy in it.
Satellite
a natural or artificial object that revolves around another bigger object in space
Impact Crater
A round pit left behind on the surface of a planet after a smaller object strikes the surface.
Axis of Rotation
An imaginary line about which a turning body such as Earth rotates.
Revolution
the orbiting of an object around another object, such as the Earth in its orbit around the sun.
Season
a period of the year determined by the position of Earth as it revolves around the sun
Equinox
In an orbit, a position and time in which sun shines equally on both hemispheres.
Solstice
either of the two times in the year, the summer solstice and the winter solstice, when the sun reaches its highest or lowest point in the sky at noon, marked by the longest and shortest days.
Mare
A large dark plain of solidified lava on the moon.
Eclipse
an event durning which one object in space casts a shadow onto another.
Umbra
the fully shaded inner region of a shadow cast by an opaque object, especially the area on the earth or moon experiencing the total phase of an eclipse.
Penumbra
the partially shaded outer region of the shadow cast by an opaque object
Astronomical Units (AU)
the mean distance from the center of the Earth to the center of the sun (about 149.6 million kilometers); used to measure distances in the solar system
Ellipse
a regular oval shape, traced by a point moving in a plane so that the sum of its distances from two other points (the foci) is constant, or resulting when a cone is cut by an oblique plane that does not intersect the base.
Terrestrial Planet
A terrestrial planet, telluric planet, or rocky planet is a planet that is composed primarily of silicate rocks or metals.
Gas giant
a large planet of relatively low density consisting predominantly of hydrogen and helium, such as Jupiter, Saturn, Uranus, or Neptune.
Asteroid
a small object made of rock or metal that orbits the sun
Comet
a body of ice and dust that travels in a long narrow orbit around the sun
Meteor
a streak of light in the sky that forms when a piece of rock from space burns up in Earth’s atmosphere (related term: shooting star)
Meteorite
a piece of rock or metal from space that strikes Earth’s surface
Geocentric
having the Earth as the center