Lately, I’ve been watching Orb: On the Movements of the Earth, an anime about astronomers researching heliocentric theories while evading religious persecution. I wanted to explore how geocentric orbits looked, and also view what maps of space might have looked like from other planets.

I’ve really been enjoying Orb so far, but I felt like a missed opportunity was that the show lacked visualizations that reveal how changing the reference object from which motion is calculated shows different patterns for the same movements. I really wanted to see how the complex looping curves followed by planets in the geocentric model map to the clean concentric orbits of the heliocentric model. So I decided to make my own!

Here’s what celestial orbits look like from a geocentric perspective:

Chaotic right? Bring order to the cosmos using the button above to toggle a heliocentric view instead!

Pretty cool! One caveat is that the visualization above chooses parameters for the rate of orbit and the radius of each orbit to make things look pretty. None of this is accurate, but accurate doesn’t look as nice for a quick demo. When you press the button above, the visualization changes the object that it’s treating as the origin for the coordinate system so all motion is relative to whatever the new origin is! This is cool, but I thought it might also be cool to see what the motion looks like when choosing planets other than Earth as the reference. Use the drop down below to see them all! I really like Mercury and Neptune because they highlight interesting phenomena - from the perspective of Mercury, every planet is doing a beautiful swirling dance, and from Neptune it looks like every planet orbits the sun, and that the sun orbits Neptune.

I think there’s some things that could be improved about this visualization:

• It could use a better color palette
• The “tails” of each orbit could react better when the reference is changed
• Tweaking the rate of orbit a bit more could find more visually interesting patterns

But overall, I think this is a pretty cool toy to play with!