Term
|
Definition
| A relatively small and rocky object that orbits a star; part of a category known as 'small solar system bodies'. |
|
|
Term
|
Definition
| The average distance (semimajor axis) of the Earth from the Sun, which is about 150 million km. |
|
|
Term
|
Definition
| The amount by which a planet's axis is tilted with respect to a line perpendicular to the ecliptic planev |
|
|
Term
|
Definition
| The name given to the event thought to mark the birth of the universe. |
|
|
Term
|
Definition
| A relatively small, icy object that orbits a star. Part of the category known as 'small solar system bodies'. |
|
|
Term
|
Definition
| The plane of the Earth's orbit around the Sun. |
|
|
Term
|
Definition
| The idea that the space between galaxies or clusters of galaxies is growing with time. |
|
|
Term
|
Definition
| A huge collection of anywhere from a few hundred million to more than a trillion stars, all bound together by gravity. |
|
|
Term
|
Definition
| A collection of a few dozen or more galaxies bound together by gravity; smaller collections are called groups. |
|
|
Term
|
Definition
| The distance that light can travel in 1 year. |
|
|
Term
|
Definition
| The group of about 40 galaxies to which the Milky Way galaxy belongs |
|
|
Term
|
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
|
Definition
| An object that orbits a planet. |
|
|
Term
|
Definition
| The process in which 2 (or more) smaller nuclei slam together and make one larger nucleus. |
|
|
Term
|
Definition
| The portion of the entire universe that, at least in principle, can be seen from Earth. |
|
|
Term
|
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
|
Definition
|
|
Term
|
Definition
| The orbital motion of one object around another. |
|
|
Term
|
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
|
Definition
| A large, glowing ball of gas that generates energy through nuclear fusion in its core. |
|
|
Term
|
Definition
| Clusters of cluster of galaxies, groups of galaxies and individual galaxies. The largest known structures in the universe. |
|
|
Term
|
Definition
| The sum total of all matter and energy. |
|
|
