What Is Uranus Made Of? Does It Have Water?

Written by Drew Wood
Updated: May 16, 2023
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Uranus is one of the most unusual planets in our solar system. It has a tilted axis, so its poles point east and west rather than north and south. This means each hemisphere of the planet gets 42 years of sunlight followed by 42 years of darkness! It has a thin system of 11 rings that were only discovered in 1977 by a space probe flyby. It has the coldest temperature of any of our planets, averaging -357 degrees Fahrenheit (-216 degrees Celsius). And it has a unique, gorgeous pale blue color. But what is Uranus made of? Does it have water? If so, maybe that is the explanation for its color. We’ll answer those questions and more about this weird, wonderful planet.

Uranus has 11 rings and 27 moons.


Key Points

  • Uranus is the seventh planet in our solar system. It is one of four “giant planets.”
  • It is dim but can be seen with the naked eye.
  • It’s the first planet to be identified with a telescope.
  • The planet is made up of a rocky core, a semi-frozen liquid mantle, and a thick atmosphere.
  • It gets its blue color from methane gas.
  • It has trace amounts of water, far outweighed by other elements.
  • Uranus has 11 rings and 27 moons.
  • It is the coldest planet in the Solar System, even though it is not the furthest planet from the Sun.

Uranus: Background

The seventh planet in the solar system, Uranus is called one of the “giant planets” together with Jupiter, Saturn, and Neptune because of its immense size. It’s possible to see it with the naked eye, but just barely, as it has a magnitude of only 5.38-6.03. A magnitude of 6.5 is considered to be the very lowest that is visible to the human eye without a telescope or binoculars. Ancient astronomers thought it was just another star, but in 1781 William Herschel used a telescope to discover that it was actually a planet. It was named in honor of Ouranos, the ancient Greek god of the sky. Scientists today think that Uranus may have been impacted by a large asteroid or wandering planet early in its formation, which tilted it on its axis so that its poles point East and West rather than North and South.

greek mythology

The name of Uranus is derived from Greek mythology.


Uranus: Vital Statistics

  • The diameter of Uranus is 51,118 km (31,748.12 mi), which is 4 times wider than Earth. If Uranus were a softball, the Earth would be a nickel compared to it.
  • The surface area of the planet is 8.1156 × 109 km2 (3.13355 x 109 mi2).
  • Its mass is the smallest of the giant planets, at 8.681 × 10^25 kg (1.913839 × 1026 lbs.). This is 14.5 times more massive than Earth. This means it has much stronger gravity.
  • It has a small rocky core about half the size of Earth, surrounded by the mantle: a partially frozen ocean. Above this is a thick atmosphere.
Comet, asteroid, meteorite flying to the planet Earth

Astronomers think Uranus was hit by a very large asteroid billions of years ago, which resulted in the planet being tilted on its axis.


What is Uranus Made of?

The core of Uranus is thought to be made of iron, nickel, and silicate. The temperature at the core is about 9,000° Fahrenheit (4,982° Celsius), which sounds hot but is cooler than the core of other planets. And the planet as a whole is so cold, it radiates almost no heat into space as other planets do. The mantle of Uranus is a partially frozen ocean made of water, ammonia, and methane ice. But not all that methane ice is actually ice: chemical processes actually turn some of that methane into actual diamonds! The atmosphere of Uranus is made of hydrogen, helium, a little methane, and trace amounts of water and ammonia.

So, the answer is yes, Uranus does have water, but no the water is not the reason for the planet’s light blue color. That is the result of methane, which is much more plentiful in the planet’s chemical composition. On Earth, natural gas is made mainly of methane, so if you have a gas stove, the color of the flame is close to the color of Uranus.

More Questions

We’ve answered the questions we started with, but there are so many more we could ask. Why does Uranus have 27 moons, and what is each of them like? How did its ring system form, and why isn’t it as big as Saturn’s? Is there any way we could harvest methane, water, or even diamonds from this planet? We encourage you to continue learning about Uranus!

The photo featured at the top of this post is © iStock.com/IncrediVFX

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About the Author

Drew Wood is a writer at A-Z Animals focusing on mammals, geography, and world cultures. Drew has worked in research and writing for over 20 years and holds a Masters in Foreign Affairs (1992) and a Doctorate in Religion (2009). A resident of Nebraska, Drew enjoys Brazilian jiu-jitsu, movies, and being an emotional support human to four dogs.

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