Uranus



5 Facts about Uranus

There are many fun facts about the 7th planet from the Sun, Uranus. Surprisingly, Uranus is quite a mysterious and fascinating planet. Here is a list of 5 interesting facts about this planet.

1. Uranus is the coldest planet in the entire solar system

Uranus orbits around the Sun from a distance of 2.88 billion km. Yet, Neptune is about 2 billion km farther from the Sun than Uranus. The strange thing is that Uranus is extremely cold, even colder than Neptune. Uranus absorbs more heat from the Sun than it gives off. The other large planets have extremely heated cores and radiate infrared radiation. Something has made the core of Uranus cool down to the extent that very little heat is radiated. It is so cold there that the temperature of the cloud tops on Uranus can decrease to 49 K.

2. Uranus is turned over and rotates on its side

This is the only planet in our solar system that does not rotate its axis, with a similar tilt as the Sun’s. The other planets are a bit tilted, yet not drastically like Uranus’s 99 degree tilt. The planet is completely rotating on its side. Imagine that all the other planets resemble a spinning top as they orbit around the Sun, while Uranus is the oddball that looks like a ball rotating on its side.

3. A day in the north pole of Uranus lasts 84 Earth years

A Uranian day is only 17 hours, but the planet’s tilt causes one pole or the other to be pointed towards the Sun. Only one pole at a time can be facing the Sun. Therefore, while standing on the north pole of Uranus, you could witness the Sun rising in the sky, circle around for 42 years and finally go down below the horizon. When the sun goes below the horizon, you would have 42 years of darkness.

4. Uranus contains rings

We all know that Saturn has a huge set of rings. However, Uranus has the second most drastic set of rings in the solar system. In contrast to Saturn’s bright, icy particles, the rings of Uranus are quite dark and narrow. Many astronomers think that Uranus’s rings formed recently and not when the planets were formed.

5. Uranus is 1st planet discovered in modern age

Most of the other planets were visible to the naked eye and discovered in ancient times. Uranus, however, was the first planet to be discovered after the telescope was invented. In 1690, John Flamsteed was the first to record Uranus, but he had mistaken the planet for a star. Yet, Sir William Herschel’s observations in 1781 was what made astronomers realize that it was actually a planet. Originally, Herschel wanted to call the planet “George’s Star” after King George III, but more astronomers settled with the name Uranus.

A few other interesting facts about Uranus are…

  • It has only been visited one time
  • It has 27 moons
  • It can be seen without a telescope or binoculars.

Initial Uranus Images Amazed Us

Uranus was discovered on March 13, 1781, but after more than 200 years of continued investigation, there was still a great deal left unknown about the planet. In 1986, the NASA Voyager 2 craft attempted alleviate this problem. Voyager 2, which is still actively traveling in the outward regions of our solar system, was given the task of gathering important information about Uranus. NASA’s Voyager probe was able to take thousands of high resolution photographs and collect important data that would give scientists more information about Uranus than they were able to acquire in the last two centuries.

The Voyager 2 made many important and shocking discoveries when it passed Uranus in 1986. It is now known that Uranus has 21 moons orbiting the planet, but prior to Voyager’s mission, scientists were only aware of five. Voyager was able to quickly discover ten new moons, as well as discovering two additional planetary rings, which brought the known total to eleven. Close up photos of Uranus’s moons revealed shocking geological features to scientists. Though they previously believed the moons would be dark, featureless chunks of ice, Uranus’s moons actually revealed river-like canyons, craters and a host of other distinctive features. After the investigation of the planet’s moons, Voyager 2 was able to gather information about specific planetary features. Voyager gathered data about the planet’s chemical composition, axis rotation, unique weather patterns, magnetic field and planetary tilt. The investigation revealed a variety of shocking discoveries. Uranus has the most unique axial tilts in our solar system with a tilt of 97.7°. In more basic terms, this means that Uranus actually rotates on its sides, which translates to the planet’s north and south poles being located where most planets’ equators would be found. Voyager 2 also discovered oddities within Uranus’s magnetic field. The previously held theory about the planet’s magnetic field, which believed that Uranus’s magnetic field would correlate with solar wind, was disproved after Voyager’s flyby. In actuality, the magnetic field is not aligned with the planet’s center–it can actually be found closer to the planet’s South Pole–and the field is asymmetric. The result of this non-traditional magnetic field orientation is varying strengths at opposing poles.

Voyager 2 would continue on its mission to Neptune and beyond with many questions still unanswered and more discouraging yet, many new questions created. Scientists are still struggling to try to explain for Uranus’s many unique features. The fact that the planet rotates on its side and has an asymmetric magnetic field goes against many preexisting beliefs about planetary formation. The terrain of Uranus’s moons raises many questions about how the satellites were created and what cosmic events led to the formation of valleys and craters. Though it may be years before these questions are answered, the value of the Voyager 2 flyby is undeniable. To this day, Voyager 2 is the only space craft that has studied Uranus and played a large role in shaping the understanding of the planet that scientists have today.

Who Discovered Uranus

The 7th planet in our Solar System, Uranus, was also the first to be discovered after the invention of the telescope. Even though the planet is quite dim, it is visible to the naked eye during clear skies. Sir William Herschel accidently discovered Uranus on March 13, 1781. Before Herschel, nobody had any official records of the planet. Therefore, he is the original discoverer. He used his strong home-made telescope to observe a region in the sky that was in the constellation of Taurus, but later he noticed it was quite large for a star. At first, he recorded a discovery of a faint object that he speculated to be a nebulous star or perhaps a comet. Herschel was almost so certain that the object was a comet that he presented it as a comet to the Royal Society. By doing this, he found out from the Astronomer Royal, Nevil Maskelyne, that the object lacked a tail and orbited around the Sun like the rest of the planets. This discovery impressed King George III of England so tremendously that he rewarded Herschel a yearly stipend of 200 pounds. As a form of respect to the king, Herschel originally wanted to name the new found planet, Georges Star. However, the international astronomy community pushed more for Uranus, a Greek name, while the rest of the planets were named after Roman gods. Other than the Astronomer Royal, other astronomers contributed in the conclusion of Uranus being a planet rather than a star. Anders Johan Lexell, a Russian astronomer, was first to calculate the orbit of the object. The new objects almost circular orbit is what allowed him to conclude that it was a planet after all.

Moreover, about a century earlier, there was another person who had documented the observation of Uranus. This man was John Flamsteed. From 1750-1769, Pierre Lemonnier, a French astronomer, observed the planet many times as well. They both thought that the object was a star. Therefore, they are not accounted for as the original discoverers of the planet because they were not the ones to recognize it as a planet. Furthermore, better details about Uranus were more observable over time as higher quality telescopes were invented. In 1986, the first and only spacecraft from Earth so far was able to land on Uranus. This spacecraft was NASAs Voyager 2 that flew within 8,500 km of Uranuss cloud tops. During this voyage, NASA discovered 10 new moons and 2 new rings around the planet.


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