Space Vocabulary Flashcards
the curved path, usually elliptical, described by a planet, satellite, spaceship, etc., around a celestial body, as the sun
Orbit
The sun together with all the planets and other bodies that revolve around it
Solar system
The large system of stars held together by mutual gravitation and isolated from similar systems by vast regions of space
Ex. The Milky Way
Galaxy
The totality of known or supposed objects and phenomena throughout space; the cosmos; macrocosm
Universe
Satellite
a device designed to be launched into orbit around the earth, another planet, the sun, etc
Impact crater
Circular depression on a planet formed by a hypervelocity impact of a smaller body
Axis of rotation
a rotation is a circular movement of an object around a center (or point) of rotation . A three-dimensional object always rotates around an imaginary line called a rotation axis. If the axis passes through the body’s center of mass, the body is said to rotate upon itself, or spin
Revolution
a radical and pervasive change in society and the social structure, especially one made suddenly and often accompanied by violence.
Season
one of the four periods of the year (spring, summer, autumn, and winter), beginning astronomically at an equinox or solstice, but geographically at different dates in different climates
Equinox
the time when the sun crosses the plane of the earth’s equator, making night and day of approximately equal length all over the earth and occurring about March 21 (vernal equinox or spring equinox) and September 22 (autumnal equinox)
Solstice
either of the two times a year when the sun is at its greatest distance from the celestial equator: about June 21, when the sun reaches its northernmost point on the celestial sphere, or about December 22, when it reaches its southernmost point
Mare
any of the several large, dark plains on the moon and Mars: Galileo believed that the lunar features were seas when he first saw them through a telescope
Eclipse
the obscuration of the light of the moon by the intervention of the earth between it and the sun (lunar eclipse) or the obscuration of the light of the sun by the intervention of the moon between it and a point on the earth (solar eclipse)
Umbra
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
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
a unit of length, equal to the mean distance of the earth from the sun: approximately 93 million miles (150 million km).
Abbreviation: AU
Ellipse
a closed, symmetric curve shaped like an oval, which can be formed by intersecting a cone with a plane that is not parallel or perpendicular to the cone’s base. The sum of the distances of any point on an ellipse from two fixed points (called the foci) remains constant no matter where the point is on the curve
Terrestrial Planet
Inner planet
Gas Giant
one of the four planets in our solar system that are composed chiefly of hydrogen and helium, namely Jupiter, Saturn, Uranus, and Neptune
Asteroid
also called minor planet. Astronomy. any of the thousands of small bodies of from 480 miles (775 km) to less than one mile (1.6 km) in diameter that revolve about the sun in orbits lying mostly between those of Mars and Jupiter
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 transient fiery streak in the sky produced by a meteoroid passing through the earth’s atmosphere; a shooting star or bolide
Meteorite
any of the small bodies, often remnants of comets, traveling through space: when such a body enters the earth’s atmosphere it is heated to luminosity and becomes a meteor
Geocentric
having or representing the earth as a center
