Tides draft V2

Second draft of the tides illustration. The illustration explores how interactions between solar and lunar tidal components cause daily and monthly tidal height patterns.

UPDATE: Final illustration posted - Lunar and Solar Tides

The illustration shows a rotating Earth and the Moon orbiting the Earth. An arrow indicates the Sun's position. The Earth rotates around its axis once every 24 hours. The Moon completes a full orbit of the Earth once every lunar month (29.53 days).

Status V 2.0
  • A "start/stop" button has been added
  • The observer (shown as a red dot) starts at local midnight.
  • time since the illustration starts is show in days and hours in upper right hand corner.
  • The Earth rotates once every 24 hours.
  • The Moon orbits the Earth once every 29.53 days.
  • Two thin lines show the orientation of the lunar (white) and solar (yellow) gravitational forces.
  • The Sun's gravitational force is 1/2 that if the Moon's.
  • The lunar gravitational force rotates to remain oriented with the Moon as the Moon orbits the Earth.
  • A blue oval indicates relative water height around the globe. The shape of the oval changes as the orientation of the Sun and the Moon change.
Previous Version:
Next Steps
  • Add controls to reset and incrementally advance the illustration.
  • Add a reporter for number of lunar days.
  • Make a graph at the bottom showing change in water height at the observer's position as the Earth rotates.