Uranus is the coldest planet in the solar system, although not the most distant from the Sun. This giant was discovered in the XVIII century. Who discovered it, and what are the satellites of Uranus? What is special about this planet? Description of the planet Uranus read below in the article.
Features
This is the seventh planet from the Sun. It is the third in diameter, it is 50,724 km. Interestingly, Uranus is 1,840 km larger in diameter than Neptune, but Uranus is smaller in mass, making it the fourth largest heavyweight in the solar system.
The coldest planet is visible to the naked eye, but a telescope with a hundredfold magnification will allow you to see it better. The moons of Uranus are much harder to see. There are 27 of them in total, but they are significantly removed from the planet and much dimmer than it.
Uranus is one of the four gas giants, and together with Neptune forms a separate group of ice giants. According to scientists, the gas giants arose much earlier than the planets that are part of the terrestrial group.
Discovery of Uranus
Due to the fact that it can be seen in the sky withoutoptical instruments, Uranus was often mistaken for a dim star. Before determining that it is a planet, it was observed in the sky 21 times. John Flemseed first noticed it in 1690, indicating it as the star number 34 in the constellation Taurus.
The discoverer of Uranus is William Herschel. On March 13, 1781, he observed the stars from a man-made telescope, suggesting that Uranus was a comet or a nebulous star. In his letters, he repeatedly pointed out that on March 13 he saw a comet.
The news about the new observed celestial body quickly spread in scientific circles. Someone said that it was a comet, although some scientists had doubts. In 1783, William Herschel declared that it was a planet after all.
The new planet decided to give the name in honor of the Greek god Uranus. All other names of the planets are taken from Roman mythology, and only the name Uranus is from Greek.
Composition and characteristics
Uranus is 14.5 times larger than Earth. The coldest planet in the solar system does not have a solid surface familiar to us. It is assumed that it consists of a solid stone core, covered with a shell of ice. And the top layer is the atmosphere.
The icy shell of Uranus is not solid. It is made up of water, methane and ammonia and makes up about 60% of the planet. Due to the absence of a solid layer, it is difficult to determine the atmosphere of Uranus. Therefore, the outer gas layer is considered the atmosphere.
This shell of the planet has a bluish green color due to the content of methane, which absorbs red rays. It is only 2% on Uranus. Other gases included inatmospheric composition is helium (15%) and hydrogen (83%).
Like Saturn, the coldest planet has rings. They formed relatively recently. There is an assumption that they were once a satellite of Uranus, which broke up into many small particles. There are 13 rings in total, the outer ring is blue, followed by red, and the rest are gray.
Orbiting
The coldest planet in the solar system is 2.8 billion kilometers away from Earth. The equator of Uranus is inclined to its orbit, so the rotation of the planet occurs almost "lying down" - horizontally. As if a huge gas-ice ball is rolling around our star.
The planet revolves around the Sun in 84 years, and its light day lasts approximately 17 hours. Day and night change quickly only in a narrow equatorial strip. In the rest of the planet, 42 years lasts a day, and then the same amount - a night.
With such a long change of time of day, it was assumed that the temperature difference should be quite serious. However, the warmest place on Uranus is at the equator, not the poles (even when illuminated by the Sun).
Climate of Uranus
As already mentioned, Uranus is the coldest planet, although Neptune and Pluto are located much further from the Sun. Its lowest temperature reaches -224 degrees in the middle layer of the atmosphere.
Researchers have noticed that Uranus is characterized by seasonal changes. In 2006, the formation was noted and photographedatmospheric vortex on Uranus. Scientists are just beginning to study the change of seasons on the planet.
It is known that clouds and wind exist on Uranus. As you get closer to the poles, the speed of the winds decreases. The highest wind speed on the planet was about 240 m/s. In 2004, from March to May, a sharp change in weather conditions was recorded: the wind speed increased, thunderstorms began, and clouds appeared much more often.
There are such seasons on the planet: the southern summer solstice, the northern spring, the equinox and the northern summer solstice.
Magnetosphere and planetary exploration
The only spacecraft that has managed to reach Uranus is Voyager 2. It was launched by NASA in 1977 specifically to explore the outer planets of our solar system.
Voyager 2 managed to discover new, previously invisible rings of Uranus, to study its structure, as well as weather conditions. Until now, many of the known facts about this planet are based on data received from this device.
Voyager 2 also discovered that the coldest planet has a magnetosphere. It has been noted that the planet's magnetic field does not emanate from its geometric center. It is tilted 59 degrees from the axis of rotation.
Such data indicate that the magnetic field of Uranus is asymmetrical, unlike the earth's. There is an assumption that this is a feature of the ice planets, since the second ice giant - Neptune - also hasasymmetric magnetic field.
