click below
click below
Normal Size Small Size show me how
Astronomy terms
A list of terms from apihelion to comets
| Term | Definition |
|---|---|
| Astronomy | The study of creation beyond our atmosphere. |
| Perihelion | Earth's closest point to the sun. |
| Aphelion | Earth's farthest point from the sun. |
| Period | The amount of time a planet takes to complete its orbit. |
| Astronomical unit | A measure used by Kepler equal to the earth's distance from the sun. |
| Vacuum | A space containing no matter. |
| Retrograde | Moving backwards (from east to west). |
| Mare | Dark patches on the surface of the moon. |
| Satellite | Any object which revolves around another object. |
| Lunar month | The amount of time it takes the moon to revolve around earth (29d 12h 44m). |
| Asteroid | A stony or metal object smaller than planets and orbiting the sun. |
| Comet | An asteroid sized object made of rock and frozen material and forms a bright tail. |
| Nucleus | The heart of a comet made of two-thirds ice and one-third dust. |
| Coma | The gas and dust forming around a comets nucleus. |
| Tail | A highly reflective streamer emitted from a comet. |
| Meteoroid | Fragments from asteroids much smaller than them. |
| Meteor | A meteoroid that has entered the earth's atmosphere. |
| Meteor shower | An event that takes place when the earth passes through a meteoroid stream causing meteor to fall much faster than normal. |
| Meteorite | A meteor that has crashed to the earth's surface. |