
| Surface | 510,900,000 km2 |
| Equatorial diameter | 12,746.32 km |
| Polar diameter | 12,713.55 km |
| Equatorial circumference | 40,075.15 km |
| Polar circumference | 39,940.80 km |
| Rotation | The earth's movement around its polar axe (24 hours) |
| Revolution | The earth's movement around the sun (365 days and 1/4) |
| Earth's axis | 23 degrees |
| Solstice | Summer: 21-22 June. Winter: 22-23 December. |
| Equinox | Spring: 20-21 March. Fall: 22-23 September. |
| Tropic of Cancer | Summer solstice, 23 degrees north. |
| Tropic of Capricorn | Winter solstice, 23 degrees south. |
| Meridian | Half circle having extremities at each of the poles. |
| Parallel | Circle produced on a parallel plan to the equator. |
| Latitude | Arc measured in degrees of a meridian according to the distance from the equator (0-90). |
| Longitude | Arc measured in degrees of a parallel between the place and the meridian of origin, Greenwich (0-180). |
| Co-ordinate | A longitude and latitude pair. |