| A | B |
|---|
| solar system | Planets, comets, asteroids, and other bodies that orbit the Sun |
| Astronomical unit | The unit used to measure things in our solar system, like planets |
| astronomical unit | 1AU is the distance from the Earth to the sun |
| Comet | Make from ice and dust it orbit the sun in a long elliptical orbit |
| Meteroid | small rocks floating in space |
| meteors | small rocks that are burning as they come towards Earth |
| Asteroid | Large rock found mainly between Mars and Jupiter |
| Gas planets | The last 4 large planets |
| Terrestrial Planets | The first 4 small planets made of rock |
| Planetary Satelite | Objects that orbit a planet, mainly moons |
| Sun | Medium size star that is the closest star to Earth |
| Stars | Produce light by doing nuclear fusion |
| Gravity | The force gets stronger when objects have large masses and are close together |
| Orbits | The paths objects take, created by the interaction of gravity and inercia |
| Light years | used to measure long distances in space. EX one star to another |
| Main Sequence | The longest stage in a star's life where it is middle aged. Found in the middle of the HR diagram. |
| Supernova | explosion of a giant star |
| Nebula | Giant clouds in space where stars are formed |
| Galaxies | Groups of billions of stars. There are several different types |
| Milky Way | The spiral galaxy where our sun is on one of the outside arms |
