101 Facts About Uranus

Uranus is the third-largest planet in the Solar System, but, surprising as this may seem, despite its colossal size, it’s one of the least dense objects in our Solar System. And like its near-twin, Neptune, Uranus is not visible to the naked eye. Keep on reading to learn a solar system sized bunch of facts about Uranus. 

Fact 1: Uranus makes a complete orbit around the Sun every 84 Earth years.

Fact 2: Uranus’ mantle is made up of a hot dense fluid mixture of water and ammonia. This water–ammonia ocean has high electrical conductivity and creates Uranus’ magnetic field.

Fact 3: To this day, only one spacecraft has visited Uranus: NASA’s Voyager 2 robotic probe.

Fact 4: The apparent magnitude, the brightness of an object in the sky, of Uranus is between +5.38 and +6.03. The naked eye can see anything less than +6.5 but anything above 5 is difficult to see by most people.

Fact 5: Titania, one of Uranus’ moons, is named after the queen of the fairies in Shakespeare’s ‘A Midsummer Night’s Dream’.

Fact 6: The difference between its minimum and maximum distance from the Sun is 1.8 AU. This is the larger difference in distance than any other major planet in the solar system.

Fact 7: Miranda, one of Uranus’ moons, has fault canyons that gouge 20 km deep into the moon’s crust.

Fact 8: Uranus experiences seasonal changes and increased weather activity as it makes its closest approaches to the Sun.

Fact 9: Uranus is the seventh planet from the Sun.

Fact 10: Uranus’ largest moon, Titania, was discovered by William Herschel in 1787.

Fact 11: Uranus’ mass is a vast number that’s almost impossible to comprehend. It has over 8.6810×10^25 kg of mass within it. Written out in full, this number looks like this: 86,810,000,000,000,000,000,000,000. To give you some idea of how vast that number is, you could easily send a medium-sized mountain’s worth of Uranus material to every one of the 400 billion stars in our galaxy, and still have a little left over for our own solar system.

Fact 12: Like Jupiter and Saturn, Uranus’ atmosphere is composed mainly of hydrogen and helium.

Fact 13: Herschel discovered Uranus using a telescope that he had built himself.


Fact 14: In Ancient Greek literature, Uranus, or Father Sky, was the son and husband of Gaia, Mother Earth.

Fact 15: The axis of Uranus is tilted at an angle of 98-degrees compared to the Sun’s orbital plane.

Fact 16: The average orbital speed of Uranus is 6.80 km/s. At that speed, Uranus could travel between London and Paris, which is a distance of 344 km in approximately 50 seconds!

Fact 17: Uranus’ brightest ring is the Epsilon ring.

Fact 18: The upper Gases atmosphere makes up a very small proportion of Uranus’ mass. It accounts for only 3.5% of the total mass of the planet yet it extends for the last 20% of Uranus’ radius.

Fact 19: While the rest of the planets in the Solar System can be thought of like spinning tops, Uranus is more like a rolling ball going around the Sun. This is because Uranus’ axis is tipped over on its side in relation to the plane of the Solar System.

Fact 20: Uranus’ mantle makes up most of the planet’s bulk and accounts for 92.5% of the planet’s total mass.

Fact 21: Uranus’ surface area is 8.1156×10^9 km2 That’s number written out in full is 8,115,600,000. That’s about 825 times the surface area of the United States of America.

Fact 22: Uranus was the first planet discovered with a telescope.

Fact 23: Uranus’ magnetic field is very strange as it doesn’t originate from the planet’s geometric center. This is unlike any other planet in the solar system.

Fact 24: Uranus’ atmosphere contains more “ices” such as water, ammonia, and methane, along with traces of other hydrocarbons.

Fact 25: The planet’s moons are all named after characters created by William Shakespeare and Alexander Pope.

Fact 26: The circumference of Uranus is 159,354.1 km. You could circumnavigate Uranus in a Formula 1 car, traveling at its top speed of 375 km/h, in just under 18 days.

Fact 27: Uranus’ core temperature is thought to be around 5000°C. That’s about 500°C less than the surface of the Sun.

Fact 28: Uranus’ surface gravity 8.69 m/s2. That’s actually just a little less than the surface gravity here on Earth.

Fact 29: Despite its sheer size, Uranus is the second least dense planet in the Solar System. The Only planet less dense than Uranus is Saturn.

Fact 30: “Uranian” is the adjective form of Uranus.

Fact 31: It has a mean density of 1.27 g/cm³. For comparison, Earth has a density of around 5.51 g/cm³.

Fact 32: The moon Miranda is a cosmic jigsaw puzzle. Its surface is a jumbled assortment of curious terrains. Miranda is thought to be composed of water, ice, and rocky material.

Fact 33: The Perihelion of Uranus, the closest distance the planet approaches the Sun on its orbit, is 2.742 billion km. That’s over 18 times further away from the Sun than the Earth is. And to give you some idea of how immensely far 2.742 billion km is, your average family car, traveling at 100km/h would take 3130 years to travel that far!

Fact 34: Uranus will have made its third complete orbit around the Sun in 2033 since being discovered in 1781.

Fact 35: It has the coldest atmosphere out of all 8 planets in the Solar System.

Fact 36: Titania’s orbit lies inside Uranus’s magnetosphere and is largely protected from the Sun’s solar wind.

Fact 37: Uranus features a similar composition to its near-twin Neptune.

Fact 38: On 10 March 1977, James L. Elliot, Edward W. Dunham, and Jessica Mink definitively discovered Uranus’ ring system by using the Kuiper Airborne Observatory.

Fact 39: In 1986, the Voyager 2 spacecraft made a flyby at a distance of 81,500km.

Fact 40: Voyager 1 couldn’t visit Uranus because the investigation of Saturn’s moon Titan sling-shot it up and out of the solar system.

Fact 41: It is thought Uranus’ extreme axial tilt was caused by a titanic impact with an Earth-sized protoplanet billions of years ago.

Fact 42: In an episode of “Doctor Who”, “The Daleks’ Master Plan”, Uranus is described as being the only location in the universe where the fictitious mineral ‘Taranium’ can be acquired.

Fact 43: The average diameter of Uranus is thought to be 50,724 km. This is approximately 4 times wider than Earth.

Fact 44: The composition of Uranus, by volume, is made up of the following gases:

  • 83% hydrogen
  • 14% helium
  • 3% methane

Fact 45: Uranus’ Polar radius, the distance from the center of the planet to the surface of the South or north pole, is 24,973 km. This is 586 km less than the equatorial radius. This equatorial bulge is caused by the spin of the planet and means that Uranus looks like a slightly flattened ball.

Fact 46: Titania is the largest of Uranus’ moons, and it is the 8th largest moon in the Solar System.

Fact 47: Uranus features a complex layered cloud structure that made it very difficult to determine the planet’s exact rotational speed.

Fact 48: Each pole gets 42 years of darkness followed by 42 years of continuous sunlight.

Fact 49: The radioactive element uranium was named after Uranus when it was discovered in 1789. The 1789 discovery of uranium in the mineral pitchblende is credited to Martin Heinrich Klaproth.

Fact 50: It’s possible that the earliest observation of Uranus was made in 128 BC by  Greek astronomer, geographer, and mathematician, Hipparchos. But, instead of a planet, he recorded Uranus as a star.

Fact 51: The ice giant is named after Uranus who was the primal Greek god personifying the sky, and one of the Greek primordial deities.

Fact 52: Floating ice-bergs made of solid diamond called ‘diamond-bergs’ are thought to float on an ocean of liquid diamond that surrounds the planet’s core.

Fact 53: Originally, William Herschel named the planet ‘Georgium Sidus’. Which means George’s Star. This was in honor of the then King of England, King George III.

Fact 54: Uranus’ internal structure consists of three layers: a rocky Iron-Nickel core in the center, an icy mantle made up of hot liquid water and ammonia (compounds such as water and ammonia are always called Ice’s in space regardless of whether they are solid or liquid) and a thick outer hydrogen/helium layer.

Fact 55: Most of its rings are very dark in color. But some rings are more reddish in color. The outer ring is blue in color.

Fact 56: Many of the cloud bands at high latitudes, close to the poles, travel around the planet faster than the planet rotates by nearly 2.5 hours.

Fact 57: Uranus has 27 moons that we know of.

Fact 58: Both planets have bulk chemical compositions that differ from that of the larger gas giants like Jupiter and Saturn. For this reason, scientists often classify Uranus and Neptune as “ice giants”.

Fact 59: Uranus has 13 known rings.

Fact 60: Uranus has a volume 63 times greater than Earth’s, which means that 63 Earths could fit inside it.

Fact 61: The planet Uranus was discovered by William Herschel on March 13, 1781.

Fact 62: Wind speeds can reach 250 meters per second near the visible surface of Uranus

Fact 63: Uranus’ surface receives about 1/400th the intensity of light that we receive on Earth. That about the same level of light as after the sun has just dropped below the horizon, but still lights the sky.

Fact 64: Deep within Uranus, carbon atoms condense together to form crystals of diamond that rain down through the mantle like hailstones. 

Fact 65: In 1986, images from NASA’s Voyager 2 probe showed that Uranus was a near featureless planet in visible light. Unlike the other giant planets in the solar system, there were no cloud bands or storms.

Fact 66: Voyager 2 returned with the first close-up images of the planet, its moons, and rings.

Fact 67: Uranus’ low density indicates that its interior must be predominantly composed of ice rather than rock.

Fact 68: Uranus orbital inclination from the ecliptic plane is only 0.773°. This means it is almost perfectly in line with Earth orbit.

Fact 69: Uranus’ core is small and makes up less than 20% of the planet by radius.

Fact 70: Titania, Uranus’ largest moon, has a diameter of only 1577.8 km. That’s less than half that of Earth’s Moon.

Fact 71: In recognition of William Herschel’s achievement of discovering Uranus, King George III gave Herschel an annual payment of £200 (equivalent to £24,000 in 2019) on condition that he move to Windsor so that the Royal Family could look through his telescopes.

Fact 72: It has the third-largest diameter of all the planets in our Solar System.

Fact 73: Uranus is the “butt” of more than a few jokes and has made a cameo in several television shows.

Fact 74: When presented his discovery to the Royal Astronomical Society, he continued to argue that the Uranus was a comet and not a planet.

Fact 75: The Equatorial rotation velocity of Uranus is 2.59 km/s. That’s over 12 times faster than a high cruise speed of a commercial jet airplane

Fact 76: The 1962 film “Journey to the Seventh Planet” is a Danish-American science fiction film focused on the planet Uranus. In the film, Uranus has not been charted by the United Nations’ Space Fleet. Therefore, in the year 2001, an international crew is dispatched to Uranus by the United Nations on a space exploration mission. They encounter many odd things on their journey – you’ll have to watch it!

Fact 77: In Chinese, Korean, Japanese, and Vietnamese, Uranus’ name is “sky king star” (天王星)

Fact 78: In 2011, the 2013–2022 Planetary Science Decadal Survey, proposed sending an orbiter and probe to Uranus between the years of 2020–2023. If it were to launch, the probe would take 13 years to reach Uranus.

Fact 79: Uranus has a total volume of 6.833×10^13 km3. This is the equivalent of just over 63 Earths worth of volume.

Fact 80: Uranus’ orbit was first mathematically determined by Finnish-Swedish astronomer Anders Johan Lexell.

Fact 81: Uranus’ Average distance from the sun is a gargantuan 2.875 billion km. That over 19 further away than the Earth is from the Sun. To put that huge distance into perspective, your average plane, cruising at a speed of 950km/h, would take 345 years to get there!

Fact 82: Uranus’ atmosphere has a minimum temperature of −224 °C.

Fact 83: A space probe’s remote-sensing capability can penetrate down to a depth of 300 km below the 1 bar (1 Atmosphere) pressure. At this depth, the temperature is a rather toasty 47°C.

Fact 84: Like Venus, Uranus rotates counter-clockwise as seen from above the North Pole, that is to say, from west to east.

Fact 85: Five of the moons are large and the rest are much smaller. The five large moons are called Miranda, Ariel, Umbriel, Titania, and Oberon.

Fact 86: The planet’s interior is mainly made up of solid ice and a rocky core.

Fact 87: Uranus’ equatorial radius, the distance from the center of the planet to the surface at the equator, is 25,559 km. That’s marginally over 4 times larger than Earth’s.

Fact 88: Titania, one of Uranus’ moons, has a diameter of 1,578 kilometers.

Fact 89: On 26 April 1781, William Herschel, Uranus’ eventual discoverer, initially mistakenly thought the planet was a comet.

Fact 90: Scientists don’t know why, but Uranus is hotter at its equator than at its poles. Even though its high axial tilt means it’s poles are almost always facing the Sun.

Fact 91: The Aphelion of Uranus, the farthest distance the planet moves away from the Sun on its orbit, is 3.008 Billion km. That is about 20 times the distance Earth is from the Sun. To give you some perspective on how huge that number is, it would take you, walking at an average pace of 2.5 km/h, 137,352 years to walk that distance.

Fact 92: Jérôme Lalande, a French astronomer, thought Uranus should have named Herschel in honor of its discoverer.

Fact 93: Herschel noticed that one of the “stars” he was looking at seemed different, and after looking at it many more times, he noticed that it moved in relation to the star in the background.

Fact 94: Between 1750 and 1769, Pierre Charles Le Monnier, a French astronomer, observed Uranus at least twelve times. 31 years before Herschel’s initial discovery. But like Herschel, he also thought it was a comet and thought nothing of it.

Fact 95: The planet also turns on its axis once every 17 hours, 14 minutes.

Fact 96: At the time of Uranus’ discovery, Erik Prosperin, a Swedish astronomer, thought the planet should be named Neptune as a tribute to the British Royal Navy. However, the idea was turned down. Fortunately, the name was later used for the planet Neptune instead.

Fact 97: William Herschel, the discoverer of Uranus, observed a ring around Uranus as early as 1789. This sighting is considered doubtful by many Astronomers because the rings are so faint. However, amazingly, Herschel did make multiple accurate descriptions of the main ring’s angle relative to Earth, its size, and its color.

Fact 98: Uranus’ axial tilt 97.77° when compared to its orbit. That means Uranus has completely rolled over onto its side.

Fact 99: Its rings are made up of fairly large particles and fine dust.

Fact 100: It has the fourth-largest mass out of the 8 planets.

Fact 101: Uranus’ magnetic field stretches 11.5 Uranian diameters ahead of it toward the sun.


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