Naked Eye Astronomy |
2. Rotation of the Earth on its axis:
3. Revolution of the Moon about the Earth:
4. Revolution of the Earth about the Sun:
5. Motions of the planets
6. Important Celestial Periods
Motion |
Period |
Comments |
Sidereal Day |
23 h 56 m 04 s |
day according to the stars |
Solar Day |
>23 h 56 m 04 s |
day according to the Sun |
Mean Solar Day |
24 h 00 m 00 s |
average Solar day |
Sidereal Month |
27 d 07 h 43 m 11 s |
Moon month with respect to the stars |
Synodic Month |
29 d 12 h 44 m 03 s |
length of the lunar phase cycle |
Sidereal Year |
365 d 06 h 09 m 10 s |
year with respect to the background stars |
Tropical Year |
365 d 05 h 48 m 46 s |
year of the seasons |
Precession |
~25,800 y |
slow rotation axis movement |