| A | B |
|---|
| terrestrial planet | any of the Earth like planets-Mercury, Venus, Mars, Earth |
| Jovian planet | Jupiter like planets- Saturn, Uranus, Neptune, Jupiter |
| nebula | a cloud of gas and/or dust in space |
| planetesimal | small, irregular shaped body formed by colliding matter |
| dwarf planet | a round object that orbits the sun but has not cleared the neighborhood around its orbit |
| asteroid | a small, rocky, body, which can range in size from a few hundred km to less than between those of Mars and Jupiter |
| comet | a small body made of rocky metallic pieces held together by frozen gases. |
| coma | the fuzzy, gaseous component of a comet's head |
| meteroroid | a small, solid particle that travels through space |
| meteor | luminous phenomenon observed when a meteroroid enters Earth's atmosphere and burns up, called a shooting star |
| meteorite | any portion of a meteroid that reaches Earth's surface |
