Planet Size Comparison Game
Streamer mode · ExitFive comparisons
Resize real objects. Trust your eye. See how close you get.
Opening your five comparisons…
About the space & planets game
Compare planets, moons, the Sun and spacecraft from across the solar system on one shared scale. Is Titan bigger than Mercury? Is Pluto smaller than our Moon? How does the International Space Station compare with a jumbo jet?
Planet and moon diameters come from NASA’s planetary fact sheets and are drawn as simple discs; rings and atmospheres are not included. Spacecraft sizes come from NASA mission pages.
Space & planets in the game
- Earth
- Hubble Space Telescope
- International Space Station
- Jupiter
- Mars
- Mercury
- Moon
- Neptune
- Pluto
- Saturn
- Sun
- Titan
- Uranus
- Venus
Common questions
Why are the planets plain circles?
Only the diameter is compared, so a disc is the clearest shape. Saturn’s rings are left out because the published diameter is the planet’s body.
Which diameter is used?
NASA’s fact-sheet diameter for planets and the Moon, and twice the published mean radius for the Sun and Titan.
Can I compare the Sun with Earth?
Some pairs are too far apart to see on one screen, so rounds keep each comparison within twenty times. The Sun appears beside Jupiter instead.
All categories · Today’s daily challenge · How the sizes are measured