Earth's orbit around the sun is elliptical, with perihelion in early January when it is closest to the sun at around 1.5 million miles less than the average distance, and aphelion in early July when it is farthest at around 1.5 million miles greater than average. The two principal motions of bodies in the solar system are rotation, with the Earth rotating on its axis eastward over 24 hours to create day and night, and revolution around the sun over 365.25 days to complete one year.

1. Celestial Navigation I Capt. Bernabe Lim INSTRUCTOR

2. Perihelion and Aphelion

4. distance about 1.5 M miles less than the mean distance

6. about 1.5 M miles greater than the mean distance

9. RevolutionVideo

12. ROTATION

14. ROTATION Rotation of Earth around axis Rotates to East Turns counter-clockwise Daytime and night time 24 hours or 1 day

15. REVOLUTION