1. When it was first discovered, Uranus wasn’t considered a planet at all. In fact, in 1690, the astronomer John Flamsteed thought it was a star. The French astronomer, Pierre Lemonier, saw Uranus numerous times between 1750 and 1769, and he thought it was a part of the Taurus constellation. Sir William Herschel observed Uranus in 1781, and he referred to it as a “comet” when he presented his discoveries to the Royal Society. Other astronomers also began to question the “comet” along with Hershel. Finally, they recognized that it was a planet, and in 1783, Hershel officially presented his new planet to the Royal Society.
2. It’s one of the only planets visible with the naked eye. Ironically, it is also the only planet that was discovered after the invention of the telescope. Perhaps this is part of the reason why it was never considered to be a planet until 1781- it was sitting under everyone’s eyes and science was not quite sure what they were looking at until they gave it a close look.
3. Uranus is the only planet whose name is derived from Greek mythology, rather than Roman mythology. It is derived from the Greek word, Ouranos. When Hershel and the Royal Society were throwing around potential names, (including Neptune) Johann Elert Bode declared that since Saturnwas the father of Jupiter, and since Ouranos was the father of Saturn, it was only appropriate to continue with the ‘father’ names. Hershel wanted to name it “George’s Star,” after King George III, however no one but King George like the idea. Bode’s suggestion decided upon throughout the scientific community and soon the planet formally known as the “comet,” became Uranus.
4. Uranus has only been visited one time. In 1986, the ‘Voyager 2’ zoomed past both Uranus and Neptune, and it took thousands of pictures. it appears to be a greenish-blue in all the pictures received from the ‘Voyager 2’, and that color can be attributed to the very small percentage of methane gas from which it is comprised. The methane absorbs infrared light and throws it back as a bluish-green.
5. A strong magnetic field surrounds Uranus. The axis of the field is tilted 59 degrees from its axis of rotation. Electrons and protons are trapped in radiation belts that encircle Uranus. These waves are too weak to be detected on Earth, however, ‘Voyager 2’ did notice the sense the waves while it was stationed in space. The axis of Uranus is also interesting. It’s at 99 degrees, meaning that it is literally on its side. It’s the only planet in the entire solar system that does this.
6. Uranus contains mostly molecular hydrogen(83%) and helium (15%) in its composition. Methane gas composes only 2% of Uranus’s atmosphere. The atmospheric pressure of Uranus is 1.2. In relation to the Earth, it is about 90-100. This means something that would weigh 100 pounds on Earth, is 90 on Uranus.
7. In 1977, nine of Uranus’s rings were discovered. There may be many smaller, incomplete rings (similar to arcs) that have low reflectivity spread throughout the larger ones. The outermost ring (epsilon) of Uranus is composed of chunks of ice several feet wide. The epsilon appears to have a grayish tinge. A type of dust is also spread across the rings. Uranus’s rings are not like Jupiter’s or Saturn’s. Jupiter and Saturn have rings that were probably made alongside each planet’s formation. Scientists believe that Uranus’s rings are relatively new, and that they were not made when the planet was formed.
8. Two of Uranus’s 27 moons, Cordelia and Ophelia, are shepherd satellites for Uranus. Shepherd satellites constrain the extent of the planetary ring through gravity. The moon’s, however, are not composed of heavy materials. When all 27 are added together, they still only equal about half of Neptune’s largest moon, Triton. Hershel discovered Uranus’s two largest moons, Titania and Oberon.
9. Uranus is the seventh planet in the solar system and it is also the coldest. The lowest recorded temperature is 49 K or -224 degrees Celsius. Neptune is considered to the twin of Uranus because it compares well in size and composition, however, it emits 2.61 times the heat of Uranus. Theories exist as to why it is so cold, but none have been proven. One interesting one states that Uranus was hit by a primordial impact that affected its internal core temperature.
10. The tilt of Uranus presents a curious situation regarding how the seasons occur. Summer in Uranus lasts 42 years. (Summer isn’t warm anyway. Uranus is the coldest planet, after all.) A day is only 17 hours. However, because it is literally lying on its side, the north pole of Uranus watches the sun dip and come up and dip and come up, but it doesn’t actually completely dip into darkness (and thus, winter) for 42 years.