PhET Interactive Simulations for Science and Math

University of Colorado

PhET Interactive Simulations

Founded in 2002 by Nobel Laureate Carl Wieman.

The simulations are written in Java, Flash or HTML5, and can be run online or downloaded to your computer. All simulations are open source.

Gravity and Orbits

“Move the sun, earth, moon and space station to see how it affects their gravitational forces and orbital paths. Visualize the sizes and distances between different heavenly bodies, and turn off gravity to see what would happen without it!”

Calculus Grapher

This simulation makes it easy to understand the relationship between derivative and integral, for example in the case of distance, speed and acceleration.

Equation Grapher

This one shows what happens when you change one of the the parameters of an equation.

NASA Scientific Visualization Studio

NASA Scientific Visualization Studio

A wonderful resource of visualizations to help understand celestial phenomena.

The SVS makes use of images from e.g. the Lunar Reconnaissance Orbiter and the Deep Space Climate Observatory to create visualizations of phenomena like eclipses of the Moon.


Moon Phase and Libration, 2017

“The Moon always keeps the same face to us, but not exactly the same face. Because of the tilt and shape of its orbit, we see the Moon from slightly different angles over the course of a month. When a month is compressed into 24 seconds, as it is in this animation, our changing view of the Moon makes it look like it’s wobbling. This wobble is called libration.”

Moon Phases 2017

2017 Eclipse and the Moon’s Orbit

Shows how the orbital plane of the Moon creates the potential for an eclipse only when the intersection with the ecliptic plane is oriented towards the Sun.

Line of Nodes

From a Million Miles Away, NASA Camera Shows Moon Crossing Face of Earth

“A NASA camera aboard the Deep Space Climate Observatory (DSCOVR) satellite captured a unique view of the moon as it moved in front of the sunlit side of Earth last month. The series of test images shows the fully illuminated “dark side” of the moon that is never visible from Earth.”