Shared Flashcard Set

Details

Astronomy Vocabulary
The Cosmic Perspective
23
Astronomy
Post-Graduate
08/23/2009

Additional Astronomy Flashcards

 


 

Cards

Term
Asteroid
Definition
A relatively small and rocky object that orbits a star; part of a category known as 'small solar system bodies'.
Term
Astronomical unit (AU)
Definition
The average distance (semimajor axis) of the Earth from the Sun, which is about 150 million km.
Term
Axis tilt
Definition
The amount by which a planet's axis is tilted with respect to a line perpendicular to the ecliptic planev
Term
Big bang
Definition
The name given to the event thought to mark the birth of the universe.
Term
Comet
Definition
A relatively small, icy object that orbits a star. Part of the category known as 'small solar system bodies'.
Term
Ecliptic plane
Definition
The plane of the Earth's orbit around the Sun.
Term
Expansion
Definition
The idea that the space between galaxies or clusters of galaxies is growing with time.
Term
Galaxy
Definition
A huge collection of anywhere from a few hundred million to more than a trillion stars, all bound together by gravity.
Term
Galaxy clusters
Definition
A collection of a few dozen or more galaxies bound together by gravity; smaller collections are called groups.
Term
Light year
Definition
The distance that light can travel in 1 year.
Term
Local group
Definition
The group of about 40 galaxies to which the Milky Way galaxy belongs
Term
Milky Way
Definition
Used both as the name of our galaxy and to refer to the band of light we see in the sky when we look into the plane of the Milky Way galaxy.
Term
Moon or satellite
Definition
An object that orbits a planet.
Term
Nuclear fusion
Definition
The process in which 2 (or more) smaller nuclei slam together and make one larger nucleus.
Term
Observable universe
Definition
The portion of the entire universe that, at least in principle, can be seen from Earth.
Term
Planet
Definition
A moderately large object that orbits a star and shines primarily by reflecting light from its star
1. Orbits a star (but is not star nor moon)
2. Massive enough to have a nearly round shape
3. Cleared the area around its orbit
Term
O
Definition
Term
Orbit (revolution)
Definition
The orbital motion of one object around another.
Term
Rotation
Definition
The spinning of an object around its axis
Term
Solar system or Star system
Definition
Consists of a star (sometimes more than one star) and all the objects that orbit it.
Term
Star
Definition
A large, glowing ball of gas that generates energy through nuclear fusion in its core.
Term
Supercluster
Definition
Clusters of cluster of galaxies, groups of galaxies and individual galaxies. The largest known structures in the universe.
Term
Universe
Definition
The sum total of all matter and energy.
Supporting users have an ad free experience!