| Word | Meaning |
|---|---|
| "M" numbers | |
| Magnetic Field | |
| Magnitude | |
| Mantle | |
| Margaret | |
| Mars | |
| Mass | |
| Matter | |
| Megaclite | moon of jupiter |
| Mercury | |
| Meteor | |
| Meteorite | |
| Methone | moon of saturn |
| Metis | moon of jupiter |
| Mimas | moon of saturn |
| Miranda | |
| Mneme | moon of jupiter |
| Moon | |
| Mundilfari | moon of saturn |
