Uranus’ unique characteristics make it one of the most exciting planets to learn about. It is the seventh planet from the Sun and the third biggest one in our solar system. Unlike all the other planets in our solar system, Uranus gets its name from Greek mythology, while the rest get theirs from Roman mythology. From the origin of its name to the number of moons it has, to its wildly cold temperature, Uranus has the ability to fascinate anyone.
Uranus is a very cold and windy planet, and it is filled with ice. There is no chance that any human could ever survive on it, let alone any spacecraft. It is for this reason that NASA has only made one trip to Uranus, so the only real images we have of it come from thirty years ago. It seems Uranus isn’t one of the most famous planets for scientists and astronomers, but with its many fascinating traits, this is pretty hard to believe. Interestingly, Uranus was the first planet to be discovered using a telescope, and a scientist didn’t discover it!
These 10 facts about Uranus only touch on a small amount of the cool things about this planet. It could take years to study everything there is to know about Uranus, so much so that some people make it their life career to do so. Who knows, maybe by the end of this article you’re going to decide you want to dedicate your life to this planet too!
10Uranus is Colder Than Any Other Planet in Our Solar System
If you think our North American winters are cold, you’ve clearly never step foot on Uranus (even though it’s impossible to). When guessing the temperature on a planet, one would assume the further it is from the sun, the colder it is – Uranus proves this theory wrong. Uranus is 2.88 billion km from the Sun, and even though it’s not the furthest from the Sun, it still has the coldest temperature. Neptune, which orbits 4.5 billion km from the Sun, is warmer than Uranus.
Astronomers separate Uranus into four sections: the outer atmosphere, the atmosphere, the mantle, and the core. These different parts of Uranus can be different temperatures at once. Uranus’ average atmospheric temperature is -224°C/-371°F. The clouds found in the outer atmosphere of Uranus are typically a bit warmer, averaging -197.2 °C/-323 °F.
So, why is this planet so cold? Well, whereas the other planets in our Solar System absorb more heat from the Sun than they give off, Uranus does the opposite. Universe Today tells us that, “While the other large planets have tremendously hot cores, which radiate infrared radiation, Uranus’ core cooled down to the point that it no longer radiates much energy.”
If Pluto were still considered a planet, Uranus would be the second coldest planet. Temperatures on Pluto can drop as low as -232.7°C/-387°F. But, since scientists decided that Pluto was too small to be a real planet, Uranus gets to keep the crown for the coldest planet in our Solar System.
9Uranus orbits the Sun on Its Own Side
Now is time for a reminder of what we learned in science class in high school. As Universe, Today reminds us, “All of the planets in the Solar System rotate on their axis, with a tilt that’s similar to the Sun. In many cases, planets have an axial tilt, where one of their poles will be inclined slightly towards the Sun. For example, the axis of the Earth’s rotation is tilted 23.5-degrees away from the Sun’s plane. Mars is similar, with a tilt of about 24 degrees, which results in seasonal changes on both planets.”
But, yet again, Uranus manages to differentiate itself from the other planets! Uranus does not have a slight tilt towards the Sun; it rotates on a 99-degree angle. So, that means it spends its days turning on its side since it moves at a right angle. Sounds a bit uncomfortable, right? This is what makes Uranus look like a ball rolling around in a circle, whereas the other planets in our Solar System look like their tops are spinning.
The question remains: why does Uranus rotate differently than the other planets? Astronomers theorize that the 99-degree angle Uranus moves on is probably the result of it colliding with another planet in the past, which left a permanent mark. This tilt is one of the reasons Uranus could never be lived on by humans, besides its insanely cold temperature and lack of firm ground.
8Like Earth, Uranus Has Four Seasons
Uranus and Earth share the commonality of experiencing four different seasons, except in extremely different ways. One of the first differences between the seasons on Earth and those on Uranus is the length of the seasons. Seasons on Earth last roughly three months, although, as we know, this length can vary depending on one’s geographical location. For the four seasons to be completed and the Earth to do a full rotation around the Sun, it takes 365 days. But, for Uranus, things don’t happen as quickly. For Uranus to make a complete orbit around the Sun, it takes a total of 84 Earth-years. That means one year on Uranus lasts 84 Earth-years – isn’t that hard to imagine? So, in this respect, a season on Uranus lasts approximately 21 Earth-years.
Due to the way Earth rotates around the Sun, its poles experience the shortest and longest daylight hours. In the Northern Hemisphere, the days are long during the hot summer months, and the nights are long during the cold winter months, and it’s the opposite for the Southern Hemisphere.
For Uranus, its “winter” season that lasts 21 Earth-years involves almost no sunlight at all, since the planet is pointed directly away from the Sun during this time. This means Uranus goes 21 years at a time without seeing the sun. During its “summer” season, Uranus is pointed directly toward the Sun. During its fall and spring seasons, a day on Uranus only lasts 17 Earth-hours, because this is how long it takes for it to spin on its axis.
7Uranus Is Not A Very Dense Planet
To be more specific, it is the second least dense planet in our Solar System, after Saturn. Universe Today explains planet density in easy-to-read scientific terms when stating, “The least dense planet in the Solar System is Saturn. In fact, with a mean density of 0.687 g/cm3, Saturn’s body is actually less dense than water (1 g/cm³). This means that the planet would float in a pool, provided it was roughly 60,000 km wide. With a mean density of 1.27 g/cm3, Uranus has the second-lowest density of any planet in the Solar System. This low density has an interesting side effect. Even though Uranus is 14.5 times as massive as the Earth, its significantly lower density means that you would only experience about 89% the force of gravity, assuming you could stand on Uranus’ cloud tops.”
But we cannot walk on Uranus’ cloud tops because the planet doesn’t have an actual surface. If a human even tried to do so, they would sink through Uranus’ outer atmosphere, which is made up of helium and hydrogen, and then land in the icy center. This experience would inevitably kill you, which is why you don’t see any astronauts attempting to do so. Its low density demonstrates that Uranus is made up of more ice than gas, although it is one of the “gas giants” in our Solar System. For this reason, it is also referred to as an “ice giant,” along with Neptune.
6Just like Saturn, Uranus Has Rings
When you think of the planet in our Solar System with rings, Saturn most definitely is the one that comes to mind. This is because Saturn has the most visible rings – so evident that you can see them with a telescope at specific points during the year. Uranus, although not as famous for it as Saturn, does have rings around it as well.
The rings of Uranus are very dark and thin. To date, Uranus has 13 known rings, which were only discovered in 1977. Each ring is comprised primarily of small particles, which astronomers believe may by the remnants of a shattered moon. Scientists have claimed that Uranus has the strangest rings in all of the Solar System, and this is probably because of how little we know about them.
Due to their faintness, they are almost impossible to see, which makes them challenging to study. Recently, researchers managed to take a thermal image of Uranus’ rings, allowing them to measure the temperature of the rings while also being able to visualize them better than ever before. With this image, they also discovered that Uranus’ most massive ring has no small dust particles within, which differentiates it from other planets’ rings in our Solar System. The rings are, instead, made up of large chunks, but we are not quite sure of what. Research about Uranus’ rings is slow-moving, but we are sure to learn more about them as science continues to improve.
5Uranus Has 27 Moons
This planet has 27 known moons, which are made up of five major moons, 13 inner moons, and nine irregular moons. The moons of Uranus are named after the characters of William Shakespeare and Alexander Pope, and because of this are known are the “literary moons.” The list of Uranus’ 13 moons in alphabetical order goes: Ariel, Belinda, Bianca, Caliban, Cordelia, Cressida, Cupid, Desdemona, Ferdinand, Francisco, Juliet, Mab, Margaret, Miranda, Oberon, Ophelia, Perdita, Portia, Prospero, Puck, Rosalind, Setebos, Stephano, Sycorax, Titania, Trinculo, and Umbriel.
Some of the moons are half made of ice, these include Oberon, Titania, and Miranda. Each moon is its own frozen world with dark surfaces. The coolest Uranian moon is Miranda, as it has some of the oldest surfaces in all of the moons of our Solar System.
The largest moon of Uranus is Titania, which measures over 900 miles in diameter and orbits Uranus from a distance of approximately 240,000 miles. Titania is the eighth largest moon in our Solar System, but it is tiny compared to Earth’s moon. Titania is only about 5% as massive as Earth’s moon. Ariel is known for being the brightest of all of Uranus’ moons, with the youngest of all surfaces. Astronomers can guess its youth in comparison to other satellites due to the minute number of craters on its surface, meaning it hasn’t faced much solar impact yet. Umbriel is the oldest and darkest of all the major moons, and Oberon is right behind it in age. They both have a lot of damage done to their surfaces.
4NASA Visited Uranus Once
The only spacecraft to ever visit Uranus is the NASA’s Voyager 2 Probe. This spacecraft was launched on August 20th, 1977, and reached Uranus on January 24th, 1986. Not exactly a quick trip. It was the first, and so far, the only mission to get an up-close view of Uranus and what the probe saw was at first glance, dawn. Voyager 2 observed very little atmospheric activity and a few cloud formations. With this flyby, a few things did become better known about Uranus. For example, thanks to Voyager 2, we now know that Uranus’ winds can reach such a high speed that they start anticyclonic storms. The uniqueness of Uranus’ clouds also became apparent, as they have different patterns depending on what hemisphere of the planet they’re in. The most critical thing Voyager 2 was able to find was the ices that exist within Uranus’ atmosphere. We knew that it was the coldest planet, but we didn’t think it had ice pieces living within its inner atmosphere.
At first, it seemed that the icy clouds that makeup Uranus’ outer atmosphere were nothing too impressive, but it’s been 30 years since Voyager 2 went by Uranus, and we’re wiser now. Astronomers have since considered sending an orbiter to Uranus, but many complications go along with doing so. Until the next machine makes its way to Uranus, we can only gaze at the planet across two billion miles of space. This leaves Uranus’ secrets up in the air, so we get to make up our own answers to our questions in our heads.
3Uranus Means God of the Sky
In Ancient Greek mythology, Uranus was the father of the sky and a child of Gaea, Mother Earth. Although he was a father of the sky that looked over all humans, he himself was apparently fatherless. This caused problems for him later in life, as he became a terrible husband to his wife Gaia and father, who was so mean to his children that he would not allow them to leave their mother’s womb. Like in most Greek myths, this father’s poor treatment of his children led one of his sons, Cronus, to rebel against him, which led to Uranus’ death.
Other stories say that Uranus had no parents at all and that he was born out of chaos. Mythology.net writes, “It was widely believed that Uranus did not have parents. Instead, he was brought to life by Chaos, the first form of the universe. But Hesiod wrote that the god was born of Gaia, who he then married. Other philosophers speculate that Uranus was born from Aether and Hemera, while Orphic Hymns suggest he was the son of Nyx.
In Ancient Greek art and the art forms that were later influenced by it, Uranus is typically characterized as an old man with white hair. He is always shown with a depressed look on his face. Since he was understood to be the God of the Sky, he is usually put above Earth in paintings.
2Uranus Rules the Zodiac Sign Aquarius
If you’re not into astrology, your first thought was probably: what the heck does that mean? Well, there’s a more exciting answer to that question than you say assume! Ask Astrology explains Uranus’ relation to the zodiac by saying:
“While Saturn is all flashy and Jupiter is all dramatic, Uranus remains to be the unique planet. It is referred to as “Uranus the bizarre.” Since supernatural study influences the planet Uranus, psychological capabilities are at its peak.
Since Uranus rules the Aquarius zodiac sign, it is primarily concerned with encouraging leadership properties. The fact that people associated with this planet are not very emotional as they can end up being better leaders. Supporting the idea of radical change and bringing improvement also explains to them as being a good leader. Uranus is also responsible for bringing about the cool and calm side of the people. While these people might or might not like to socialize, they know how to make things better. They might bring this improvement on a small or larger scale, but the improvement is sure to come. The negative characteristics of Uranus include emotional breakdown, phantasms, chaos, sexual perversion, unacceptable behavior, egoism, and selfishness.”
Uranus, since it was the first planet to be discovered using a telescope, is also meant to represent scientific innovation. This all may seem silly to you, but astrology has existed for longer than most fields of study that we have today – so it could very well hold a lot of truth.
1Uranus Was Discovered in 1781
On March 13th, 1781, the English astronomer William Herschel discovered the planet of Uranus, except he didn’t think it was a planet yet. His name is entirely unheard of, but Herschel was both a composer and an astronomer. Before this famous date, Herschel had been searching for double stars in the sky using a telescope in his backyard. One day, he noticed a disc-shaped object in between all of the sky’s stars. Herschel initially labeled this disc as a comet. He then sent his findings to the Astronomer Royal Nevil Maskelyne. Once word got out about this disc, the Russian academician Anders Johan Lexel came on the scene soon after to take a look at Herschel’s finding. After computing the orbit, Lexel concluded that this disc was no comet, and instead, it could be a planetary body. Another astronomer from Germany, by the name of Johann Elert Bode, noticed its almost perfectly circular orbit, which led him to conclude that it was a planet rather than a comet.
“The object was soon universally accepted as a new planet. By 1783, Herschel acknowledged this to Royal Society president Joseph Banks: “By the observation of the most eminent Astronomers in Europe it appears that the new star, which I had the honor of pointing out to them in March 1781, is a Primary Planet of our Solar System.”
If you know where to look in the night sky and you have immensely good vision, you may be able to see Uranus without a telescope. It’s not a very bright planet, and can often be confused for a comet, a mistake William Herschel made in the midst of his discovery, but it can be seen on some nights. If you are good with spotting constellations, it is usually found located in front of Aries the Ram and close to Pisces the Fishes. According to some sources, the next time Uranus may be able to be seen from Earth is on January 31st, 2020 – so keep your eyes peeled!
Uranus came to be when gravity pulled swirling dust and gas together to create this ice giant that is now known as a planet. So, when Greek mythology claims that the god Uranus was made out of chaos, we can see where they got the idea. Uranus is blue because of methane gas in its atmosphere. This gas is known to reflect the color blue, which is why when we get a glimpse of Uranus in the sky, it always looks blue.
Uranus cannot support life as we know it, and this fact definitely won’t change in our lifetime. We still have so much to discover about this icy blue planet. Uranus continues to be a mysterious planet with many unanswered questions attached to it and is going to remain this way until another spacecraft is sent to get a better look at it.