Tools / Follow a question
Make space
a little more tangible.
Big numbers make more sense side by side. Pick two worlds, compare their measurements, and discover just how different a planet can be.
A little play. A big discovery.
Size It Up Space Game
How big is Mars next to Earth? Resize two smiling worlds, check your guess, and discover the real science behind their sizes. Made for curious little explorers.
Let’s playInteractive / Free to use
Planet Explorer
Compare any two of the eight planets. See their diameters on the same scale and switch between miles and kilometers.
- Mean diameter and distance from the Sun
- Year length and rotation duration
- Suggested comparisons and shareable links
A place to start