AVP Teachers' Notes

These simulations were designed to be used in the classroom, or in the lab by students, as demonstrations of various aspects of planetary motions. This is an ongoing process, so pages will be added and modified in the future. Please send any suggestions to the address below. Thank you.

Currently there are several simulations which can be grouped into two or three modules:

Spatial Relations

This set shows the solar system from different viewpoints to help students visualize our place in the solar system.

The "Visible" Solar System shows the solar system (Sun through Saturn) from above while showing the planets' journey along the ecliptic, through the signs of the zodiac.

Using The World's Horizon, students can see the positions of the Moon, Sun, and planets as the would look in the sky from anywhere on Earth, and at any time. Demonstrations of sun set/rise points and times as functions of latitude and time of year can be made. This simulation can also be used to determine good evenings for viewing the various planets.

Orbital Dynamics

This set displays the nature of the way bodies orbit their primaries.

The Mercury/Sun Simulation illustrates the 3:2 harmonic resonance of Mercury's rotation rate to its orbital period. Students can see how this resonance enables Mercury's tidal bulges to remain aligned with the Sun as Mercury makes its closest approaches. In addition, students can see that Mercury's orbit is an ellipse, and can see how its velocity changes as a function of distance from the Sun.

The Earth/Moon System Simulation shows the spatial relationships between Earth, Moon, and Sun that give rise to the phases of the Moon, as well as solar (both annular and total) and lunar eclipses. An edge-on view demonstrates why eclipses don't occur every month. Also easy to show are the differences between synodic and sidereal months. "Craters" on the Moon allow students to see the Moon's rotation, and the difference between the Moon's "dark" and "far" sides.

The Jovian System provides a good visual demonstration of the effect of gravity on orbital velocity, using the Galilean satellites of Jupiter. The closer satellites (Io, Europa) can be seen orbiting more quickly due the the increased effect of Jupiter's gravity.

Historical Solar Systems

This simulation shows various solar system models used throughout history. They include:

Ptolemy's geocentric system (simplified), Tycho's hybrid system, and Copernicus' heliocentric system (simplified). For comparison, also see The "Visible" Solar System, our current model.

These demonstrate the increasing complexity needed to get the earlier system to correctly predict observed planetary motions and provide a great example of the principle of Occam's Razor.

Planetarium Homepage | Paul Stoddard Homepage | Geology Homepage

pstoddard@niu.edu

October, 2012