The Planet Uranus

Reading and Assessment

Uranus, the seventh planet from the Sun, was discovered by William Herschel on March 13, 1781.[1]

     
Uranus as seen from Voyager 2  
     
Uranus as seen from Voyager 2
en:Image:Uranus_symbol.ant.png Uranus Facts:
  • Uranus's rings look white in pictures, but they are really made of asphalt-colored material. 
  • When it was first discovered, Uranus was mistaken for a star. It was named "34 Tauri". 
  • Uranus rotates on its side like Pluto. 
  • Uranus is the only planet to be named after a Greek god, not a Roman one. 

 

How big is the planet?

Comparison of the size of Uranus and the Earth
Comparison of the size of Uranus and the Earth

Uranus is 51,118 km or about four Earths wide. It is the third widest and fourth heaviest planet in the Solar System.[2]

What is its surface like?

Uranus has no surface that you could stand on without going deep into the atmosphere. Under the atmosphere, there may be a uniform mixture of rock and ice.[3]

What are its rings like?

Uranus has eleven rings. These rings are made of large rocks up to 10 m wide! They are dark in color and very hard to see. They were discovered by accident in 1977. Scientists were studying a bright star near Uranus. However, the star's light was blocked before and after it disappeared behind the planet. From this, they figured out that the planet had a ring system.[4]

What are its moons like?

Uranus's rings and moons
Uranus's rings and moons

Uranus has 27 known moons, which places it third in the Solar System for number of moons! The five main ones are Miranda, Ariel, Umbriel, Titania and Oberon.[5]

Miranda

Miranda is the smallest and closest of Uranus's major moons. It is mainly made of ice and rock. Miranda's surface has grooves, cliffs, and valleys. The moon was named after a character in "The Tempest," a play by Shakespeare.[6]

Ariel

Ariel is made of rock and ice. Ariel has many valleys, but not many craters. Ariel was named after a spirit in "The Tempest" by Shakespeare.[7]

Umbriel

Umbriel is made of lots of ices and some rock. It is also the darkest of Uranus's major moons. Umbriel was named after a character in the poem "The Rape of the Lock" by Alexander Pope.[8]

Titania

Titania is the largest moon of Uranus. It is mostly ice and rock. The surface is covered with canyons. It was named after the Queen of the Fairies in "A Midsummer's Night Dream," a play by Shakespeare.[9]

Oberon

Oberon is the outermost of the major moons of Uranus. It is made of the same things as Titania. It has many craters. Some of them have white rays around them and dark crater floors. It was named after the King of the Fairies in "A Midsummer's Night Dream".[10]

Other moons

There are 13 tiny moons known to be orbiting Uranus inside Miranda's orbit. Nine more tiny moons are known to be in big orbits beyond Oberon's orbit.[11]

How long is a day on Uranus?

One day on Uranus is about 17 Earth hours long. Uranus spins on its side, maybe because of a big impact early in the history of the Solar System.[12]

How long is a year on Uranus?

One year on Uranus would be 30,708 days or 84 years on Earth.[13]

What is it made of?

Unlike Jupiter and Saturn, Uranus is thought to be made mostly of rock and ices. The gases in its atmosphere are mostly hydrogen and helium. Other gases found in smaller amounts are ammonia, water, and methane.[14]Uranus' blue color comes from methane clouds, which absorb red light and reflect blue light.[15]

How much would Uranus's gravity pull on me?

If you were floating close to the cloud tops of Uranus, you would be pulled down with a force about nine tenths as strong as Earth's gravity.[16]

Who is it named after?

Uranus was named after Ouranos, the Greek name for the sky. According to Greek mythology, Ouranos was the husband and son of Gaia, Mother Earth.[17]

References

TEST YOUR KNOWLEDGE OF THE MATERIAL

1) How long is a day on Uranus?

Please enter your answer in the space provided:


hours.

2) A 100 pound object on Earth would weigh how many pounds on Uranus?

pounds.

3)How long does it take for Uranus to travel around the Sun?

years

Multiple Choice Questions

1. How is Uranus different from Jupiter and Saturn?
a) Uranus is greenish in color
b) Uranus is thought to be made mostly of rock and ices
c) Uranus has more moons than either Jupiter or Saturn

2. What is the largest moon of Uranus?
a) Titania
b) Ariel
c) Umbrial
d) Oberon

3. Which statement is not true about the planet Uranus?
a) Uranus is the eight planet from the Sun
b) Uranus has no surface that you could stand on without going deep into the atmosphere
c) Uranus has 27 known moons
d) Uranus has rings but they are dark in color and difficult to see

4. The atmosphere on Uranus is
a) mostly hydrogen and helium
b) mostly methane gas
c) similar to Jupiter and Saturn's atmosphere
d) none of the above

5. Who was Uranus named after?
a) The planet Uranus is named after the Greek God of War
b) Uranus is named after the Roman god of the sea
c) Uranus was named after Ouranos, the Greek name for the sky.
d) none of the above

 




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