Uranus is the seventh planet from the Sun, and has the third-largest diameter in our solar system. It was the first planet found with the aid of a telescope, Uranus was discovered in 1781 by astronomer William Herschel, although he originally thought it was either a comet or a star.It was two years later that the object was universally accepted as a new planet, in part because of observations by astronomer Johann Elert Bode. Herschel tried unsuccessfully to name his discovery Georgium Sidus after King George III. Instead, the scientific community accepted Bode's suggestion to name it Uranus, the Greek god of the sky, as suggested by Bode.
Uranus is one of two ice giants in the outer solar system (the other is Neptune). Most (80% or more) of the planet's mass is made up of a hot dense fluid of "icy" materials – water, methane, and ammonia – above a small rocky core.
Uranus probably has three layers inside it: a rocky core at the center, an icy mantle surrounding that, and an outer gas envelope of hydrogen and helium. The core of Uranus is very small, with only half the mass of the Earth. The largest portion of Uranus is the icy mantle.