Gravity is what keeps your feet firmly planted on the ground. That’s why the average person can only jump as high as 1.5 feet straight up. But what if we had to live on another planet — say, Venus or Saturn? Let’s find out what difficulties we’d have to endure there. How high could you jump on other planets? The gravity on Mercury, for example, is less than half that on Earth, so you’ll be able to jump about 4 ft high. But if you were to jump being on Venus, you’d make it just shy of 1.7 ft high because the mass and size of Earth and Venus are almost similar with Venus being a little smaller.