INSIDE URANUS

1 Hydrogen-helium atmosphere

Although by percentage the atmospheric composition of hydrogen and helium is similar to the other giant planets, by mass it’s very low.

2 Silicate iron-nickel core

The core is thought to be a rocky, iron-nickel body 0.5 to 3.7 times Earth’s mass. The precise figure is currently unknown due to the difficulty of calculating it.

3 Fluid icy mantle

Made of ammonia, water and methane ices, the mantle is the bulk of Uranus’ mass, increasing in temperature and pressure towards the core.