Planet Picker Wheel

1. What it is

This is a spinning wheel loaded with the 8 planets, Pluto, and the Sun by default. Spin it, and it lands on one of them at random, then shows a short card with a few real facts about whatever came up — the body's type, its distance from the Sun, its moon count, that kind of thing.

You're not stuck with the default list. Swap in a preset for just the rocky inner planets, the gas and ice giants, the dwarf planets, or the major moons — or clear it out and type in your own entries, including moons, fictional worlds, or anything else you want the wheel to choose between.

2. How a spin is decided

Every entry on the wheel gets an equal-size slice. The winning slice is chosen with crypto.getRandomValues(), the browser's built-in cryptographically secure random number generator, and it's chosen before the spin animation even starts — the wheel is just animating toward a result that's already been picked, not deciding as it slows down. With N entries loaded, each one has exactly a 1-in-N chance on every spin, and no spin affects the odds of the next one.

If you want to guarantee no repeats across several spins — handing out one planet per student, for example — turn on Remove Winner After Spin in the settings panel so each entry only comes up once.

3. Adding your own entries

Type a name into the input field and hit Enter to add one entry at a time — popular additions are moons like Titan, Europa, Ganymede, and Io, or dwarf planets like Eris, Ceres, Makemake, and Haumea. For a longer list, open Bulk Paste and drop in several entries at once, one per line or separated by commas, instead of typing each one individually.

The wheel needs at least two entries loaded to have somewhere to land, so check your list before hitting spin.

4. Wheel settings

You can change the spin music, adjust how long the spin takes, toggle confetti and the result popup on or off, or allow duplicate entries if you want some outcomes to be more likely than others.

Remove Winner After Spin takes the selected body off the wheel automatically once it's chosen — the setting most people reach for when assigning research topics without repeats. Clear All wipes every current entry if you'd rather start from a blank list.

5. Saving & sharing

Your entries save automatically to your browser's local storage as you use the wheel, so you don't have to rebuild your list every time you come back on the same device and browser. Clearing your browser's site data will remove them.

Built a custom wheel — say, a moon-only wheel for a specific lesson — and want someone else to see it exactly as you set it up? Click Share Wheel to copy a link. Anyone who opens it gets the same entries loaded and ready to spin.

6. Solar system data

The facts shown after each spin come from the numbers below. Click any name to load just that one body onto the wheel.

Moon counts reflect the IAU Minor Planet Center's confirmed totals as of March 2026 — Jupiter and Saturn in particular keep climbing as new, tiny outer moons are confirmed, so treat these as a snapshot rather than a permanent tally.

8 bodies hold official planet status: Mercury, Venus, Earth, and Mars are the small, dense, rocky inner planets; Jupiter, Saturn, Uranus, and Neptune are the much larger gas and ice giants, wrapped in rings and dozens of moons apiece. Pluto lost its planet status in 2006 when the International Astronomical Union set a formal definition that Pluto doesn't meet — it hasn't cleared the neighborhood around its orbit the way the 8 planets have — but it stays on this wheel because people keep asking for it.