Description

This simulation shows the view of the night sky along the ecliptic as seen from Earth. The motions displayed depict a simplified version of our solar system in which all planets have circular orbits centered on the Sun with all orbits in the ecliptic plane. The five naked eye planets are shown: Mercury (cyan), Venus (yellow), Mars (red), Jupiter (pink), and Saturn (magenta). Controls allow you to decide which planets to show, play/pause the simulation, step forward or backward in time, or reset the simulation. The simulation does NOT depict variations in the brightness of the planets (which is hard to judge), nor does the simulation correctly show whether the planet is in front of or behind the Sun (it always shows the planet passing behind the Sun even because even if it passed in front of the Sun you would not be able to see the planet).

A clock shows the elapsed time (in solar days). The simulation also includes a tool for measuring the elongation of any point from the Sun. Click the Show Elongation Tool checkbox to activate the tool. Click and drag on the red square to move the measurement line to the desired location. The elongation of that point from the Sun is then shown in the Elongation field. You can use the stepping buttons to move the measurement line by 0.1 degree in ecliptic longitude.