Space Science Flashcards
Big Bang Theory
a theory about the origin of the universe which states that the universe was at one time a very small, very condensed, very massive particle; a large explosion forced all matter out at an extremely rapid rate, and the universe has continued to expand since
Planet
a body moving in orbit around a star; large enough to clear debris in its orbit’ has enough gravity to make it round.
Earth
Quasar
an extremely bright galactic nucleus in the center of a very old, very distant galaxy, thought to be powered by a black hole at its center
Accretion
the process by which smaller particles clumped together to form bigger and bigger masses, and eventually, planets like Earth
Nebula
a gas and dust cloud in space
Orion Nebula
Halo
a region around a spiral galaxy containing clusters of old stars
White Dwarf
a small star with high density; often the size of a planet
Sirius B
Red/Blue Dwarfs
small stars; red dwarfs have low mass and low surface temperature; blue dwarfs develop from red dwarfs after the hydrogen is used up
Proxim Centauri
Irregular Galaxy
a star system without a defined shape
Large Magellanic Cloud
Normal Spiral Galaxy
a spiral galaxy with arms that extend from a nuclear region or bulge
Andromeda Galaxy
Dwarf Planet
a small planet not large enough to clear its orbit of debris
Pluto
Meteoroids
small bodies of debris from space which move into Earth’s atmosphere and can then turn into meteors
Celestial Bodies
a physical object in space which has observable characteristics
planet
Solar System
a star, as well as the planets, satellites, asteroids, and all the other objects orbiting around it. They travel together through space.
Galaxies
a system of starts and their systems held together by gravity
Milky Way Galaxy
Sedna
another dwarf planet; much farther from the sun than Pluto’ takes 10,000 years to orbit the sun
Absolute Magnitude
the actual amount of light a star gives off.
The absolute magnitude of our sun is 4.8
Milky Way Galaxy
the spiral galaxy in which our solar system is located
Binary Stars
a two-star system; the stars rotate around a common point or one star rotates around the other
Castor
Redshite
a shift in the light from a star toward the red end of the visible spectrum that is produced when the star is moving away from Earth
Barred Spiral Galaxy
a spiral galaxy with a bar of material in the central region of the galaxy; the arms extend from the bar
Galaxy NGC 1300
Red/Blue Giants
large stars; red giants have high luminosity and low surface temperature; blue giants have high luminosity and high surface temperature
Rigel (blue giant)
Background Radiation
low temperature radiation that permeates all of space; thought to be a red-shifted remnant of the big bang
Saturn
the sixth planet from the sun; an outer planet (outside the asteroid belt); the least dense planet; has a complex ring system
Protoplanet Theory
the belief that planets were small, dense regions of a nebula that were captured by the gravity of a star
Neptune
the eighth planet from the sun; an outer planet (outside the asteroid belt); methane in the atmosphere absorbs red light to make it appear blue; gives off over twice as much energy as it receives from the sun
Constellations
a star grouping which forms a pattern; we have ascribed images to the constellations
Orion
Exoplanet
Planets which orbit stars outside our own solar system
Proxim Centauri b
Stars
a gaseous body which produces radiant energy through nuclear fusion reactions
the sun; Sirius
Satellite
an object or body that orbits another object or body
Earth’s moon
Asteroids
small, rocky bodies in the sun’s orbit
Ceres
Period (of a Comet)
the amount of time it takes for a comet to orbit the sun
Halley’s Comet has a period of 75 years
Black Hole
an object with gravity great enough that it does not allow radiation or matter to escape
Earth
the third planet from the sun; an inner planet (inside the asteroid belt); only known habitable planet; 71% of surface is covered with liquid water
Spiral Galaxy
a relatively flat, disk-shaped star system with one or more arms that spirals out from the central “bulge” of stars
Spiral Galaxy
a relatively flat, disk-shaped star system with one or more arms that spirals out from the central “bulge” of stars
Mars
the fourth planet from the sun; an inner planet (inside the asteroid belt); the “Red Planet”; home to Olympus Mons, the tallest mountain in the solar system
Meteor
a meteoroid that has entered Earth’s atmosphere
Comet
a body of ice and dust in the sun’s orbit; contains a gas and dust “tail”
Halley’s Comet
Pluto
previously classified as the ninth planet from the sun; usually. now classified as a minor planet or dwarf planet; has five moons
Venus
the second planet from the sun; an inner planet (inside the asteroid belt); slightly smaller than Earth; similar density and chemical composition to Earth
Venus
the second planet from the sun; an inner planet (inside the asteroid belt); slightly smaller than Earth; similar density and chemical composition to Earth
