My Space Card
Guess which world would make you weigh the most, then find your weight and your age on all eleven worlds. Weight is a game number and nothing you pick leaves your device.
Guess first: which world would make you weigh the most?
The Moon on your birthday
Keep your card with a birthday and the Moon on that day shows here; or pick a month and day below. Every shape is from our Moon table, November 2026 to December 2027.
Birthday Moon
Why do I weigh different amounts on different worlds?
A world's pull is a number: Jupiter pulls 2.36 times harder than Earth, Mars only 0.377 times as hard and the Moon 0.165, says NASA's planetary fact sheet, checked 29 October 2026. Your weight there is your weight on Earth times that number, a game number you can skip. Your age there is how many of that world's years you have lived. Nothing you pick leaves your device.
For grown-ups
Nothing here is sent anywhere: no name, no birthday, no weight. The weight and birthday are used on this page to draw the cards, and are kept on this device only if your child taps "Keep my card". The numbers are NASA's: each world's page links its fact sheet. Weight is shown as a game number, never as a comparison, and can always be skipped.