SATURN vs. MARS Saturn, the sixth planet from the sun, is about 17 times the size of Mars, and almost 884 times as heavy! Although it is so much heavier and larger than Mars, it os only a fraction as dense. Here are some comparisons: Saturn's Radius: 60,268 km, 17 times as wide as Mars Saturn's Mass: 5.68 x 1026 kg, 884 times as massive as Mars. Saturn's Density: .69, 17% as dense as Mars.