What is the least dense planet?

The least dense planet in our solar system is Saturn, with a density of only 0.687 grams per cubic centimeter. This is less than the density of water, meaning that if there was a large enough body of water, Saturn would float in it.

Saturn's low density can be attributed to its composition. It is primarily made up of hydrogen and helium gas, with a small rocky core at its center.

Despite its low density, Saturn is the second largest planet in our solar system and has the most extensive and complex ring system of any planet. It is also home to dozens of moons, including the largest moon in our solar system, Titan.