The Uranus

Introductory text to the planet Uranus

Uranus is the seventh planet in the solar system. It was not until 1781 that the German-British astronomer Friedrich Wilhelm Herschel discovered Uranus. The six inner planets, including Earth, were known since antiquity, as they could be seen in the sky with the naked eye. Uranus is not even in favorable constellations in the sky as a planet to recognize. Rather, one might think that it is a star.

Named the planet, which is four times the size of the earth, after Uranos, the Greek god of the sky. A day on Uranus takes 17 hours and 14 minutes. This is the time the planet needs to turn once around its own axis. In contrast, a complete orbit around the sun takes 84 Earth years.
In images and observations with the telescope, the Uranus always shows in a greenish-blue color, the tendency goes more into the blue color spectrum. Frozen methane in the upper gas envelope gives the planet its color.

Uranus - facts and figures

The image on the left does not show an upside down image, because Uranus' axis tilt is 98 °. His rotation is declining. Only Mercury and Uranus are rotating in the solar system. The cause is unknown until today. A collision with another protoplanet during the early phase of the universe is suspected.

Similar to Saturn, Uranus also has a ring system which, unlike the ring planet Saturn, is invisible to the naked eye. The rings essentially consist of dust and smaller rocks, probably from the moons of Uranus. Asteroid impacts have thrown this material into orbit. As a result, the strong gravitational field of Uranus attracted these objects, which have since revolved around the planet.

Uranus's gaseous surface consists of 84% hydrogen, 14% helium and 2% methane. The closer it gets to the center of the planet, the more the pressure increases. Therefore, the gas at its critical point in the liquid state of aggregation over. The core of Uranus consists of ice and rock, possibly also heavier elements are involved.

The moons of Uranus

27 moons encircle Uranus: 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. The names are almost all borrowed from figures from William Shakespeare's works. Noteworthy are the five main moons: Miranda, Ariel, Umbriel, Titania and Oberon.

Titania is the largest of the Uranus moons with a diameter of 1500 km. Cupid with 10 km diameter the smallest Uranusmond. When summed up, the mass of the 27 Uranus moons gives just 20% of the Earth's mass.

Voyager 2 - On the way to the edge of the solar system

In 1977, the two spacecraft Voyager 1 and 2 started on their way to the edge of the solar system. For Voyager 2 was originally planned only to Jupiter and Saturn arrive. NASA did not expect the spacecraft to remain functional for such a long time to fly to other targets in the solar system, take pictures, and send them back to Earth. After successful mission, the probe was redirected towards Uranus and Neptune, where it flew by in 1986 and 1989 respectively. Since then, Voyager 2 continues to fly to the edge of the solar system. So far, more than 25,000,000,000 km have been covered. Voyager 1 and 2 are the spacecraft that is farthest from Earth, and will remain so for now. So far no further missions are planned. The majority of missions over the next 10 years will target Mars and our Moon.

Summary

Uranus is the seventh outermost planet in the solar system.

The bluish color of the planet is not caused by water, but by methane.

For a complete rotation around the Sun, Uranus needs 84 years. One turn around its own axis takes just over 17 hours.

27 moons orbit Uranus. In relation to our moon, the uranium moons are tiny.

So far only the space probe Voyager 2 really came close to Uranus.