The idea of bouncing around in the moon‘s low gravity is so appealing that an entire industry was formed to recreate the experience for kids at their birthday parties. But since walking on the moon is currently an impossible dream for most of us, it’s hard to understand just how different its gravity is compared to that of earth, or for us to comprehend what the gravity will be like when mankind reaches its next celestial destination, Mars. How can we non-astronauts tangibly grasp those differences when we aren’t going to space any time soon?

It turns out a brilliantly designed, handheld desk toy will let you see how much slower an object will fall on the moon or mars due to the very different gravity of each. “Inspired by space missions,” the Moondrop uses “simple physics” to make a slider fall at a rate equivalent to that of the gravity of the moon or Mars.

The moon’s gravity of 1.622 m/s² is roughly a sixth of our planet’s (9.807 m/s²), with Mars’ gravity of 3.711 m/s² roughly 2.6 less than earth’s. The two different forms of the Moondrop show the falling speeds of each celestial body.

Made with the “latest cutting edge technology using precision CNC machining,” the body for both versions, as well as the slider for the Lunar Moondrop, is made from “Aerospace grade aluminum,” with the Mars’s slider made out of pure copper. The design of each toy is based on physic’s “well known” Lenz’s law, which you can read about in more depth on the Kickstarter page, but the simplest explanation is “magnets.” The magnets inside create forces that slow down the slider, seamlessly mimicking the gravity of either the moon or Mars. You can remove the magnets though to return them to earth’s (boring old) gravity.