The Final Frontier



Type of Planet

Uranus is an ice giant, meaning a giant planet composed mainly of elements heavier than hydrogen and helium.

Ice giants consist of only about 20 percent hydrogen and helium in mass, as opposed to the Solar System's gas giants (Jupiter and Saturn), which are both more than 90 percent hydrogen and helium in mass.


Like the gas giants, Uranus doesn't have a firm surface. However, hydrogen and helium gases only dominate the outer edges of the planet.

Over 80 percent of the planet is made up of "icy" materials, such as water, methane and ammonia, above a small rocky core.

Uranus therefore has an atmosphere more comparable with Neptune, than with Saturn and Jupiter. Uranus's atmosphere is composed of 82.5 percent Hydrogen, 15.2 percent Helium and 2.3 percent Methane.

The dull blue color of Uranus is caused by the methane in the atmosphere, which absorbs red light and prevents it from bouncing back out into space. What see are the blue-green photons reflected into space.

Planetary Rings

Uranus has two sets of rings, an inner system of nine rings, and two outer rings.

Size (Diameter), Mass, and Density

Uranus is 4 times the diameter of Earth, and 14.5 times the mass of the Earth. Uranus is slightly larger in diameter than its neighbor Neptune, yet smaller in mass.

It is the second least dense planet in the solar system after Saturn. The density of Uranus is 1.27 grams per cubic centimeter, compared to Earth's 5.51.


Although Uranus is much larger than Earth, its gravity is only 86 percent of the Earth's. This is because Uranus is less dense than the Earth.

Magnetic Field

Uranus has a strange magnetic field. The main magnetic field of Uranus is tilted 59 degrees away from the planet's spin axis. Earth's magnetic field is also tilted, but only by 11 degrees.


Uranus has the coldest planetary atmosphere in the Solar System, with a minimum temperature of -224.2 degrees celsius. Near the core, it heats up to 4,982 degrees celsius.

Length of a Day (Rotation)

A day on Uranus lasts 17 hours 14 minutes.

Uranus is one of just two planets that rotate in the opposite direction than most of the planets (Venus is the other one), from east to west.

Axial Tilt

Uranus has an axial tilt of 98 degrees. This means, unlike all the other planets, and most of the moons, in our Solar System, Uranus spins on its side. This causes 21-year-long seasons and unusual weather.

Length of a Year (Orbit)

A year on Uranus lasts 84 Earth years.

Distance from the Sun

Uranus is the seventh planet from the Sun at 1,784 million miles.