×

More help, more resources, more learning.

KidsAstronomy.com will be joining the Education.com family!

We're so excited to continue to grow and support the parents and teachers championing children's education.
Read press release
KidsKnowIt Network is now part of Education.com!

Uranus’s Inner Moons

The planet Uranus has many fascinating worlds that orbit it. Uranus has 13 moons which lie closer to the planet’s surface than the other large moons. We call these the Inner Moons. Since the planet rotates on its side, Uranus’s inner moons also rotate up and over the planet.A Digital Illustration of Planet Uranus
 

How Were the Moons Discovered?

The distance between Uranus and Earth makes it difficult to see the smaller moons. This means they weren’t discovered until the satellite Voyager 2 found them in 1986. The satellite found that the moons are made of ice and an unknown dark substance. The satellite also discovered 10 new moons. But, Voyager 2 only did a quick flyby of the planet. Unfortunately, Uranus hasn’t gotten its own satellite to explore it yet. So almost everything we know about the planet has come from telescopes. Although the Hubble Space Telescope is strong, there are likely small moons of Uranus that we haven’t discovered.

A 3D illustration of Voyager 2 in space.

An artists rendition of Voyager 2 in space.

What Do the Inner Moons Do?

Like the other gas giants, Uranus has a system of rings. Some of the planet’s smaller moons are responsible for keeping those rings in a band. These special moons are shepherd moons. They orbit at the edges of the rings and keep dust and ice from escaping.
 

How can Moons Create Rings?

When the moons were first formed, they were not at the edge of a ring. Over millions of years, the dust and ice on the outside of the moons flew off. This dust and ice got trapped between two orbiting moons. The dust can’t escape because of the moons gravitational pull. So, the rings form between where two moons are orbiting. The shape of the ring all depends on the distance between the moons around it. If two shepherd moons are further apart, the ring formed is wider. If the moons are closer together, then the ring is more narrow. 

A gif showing how shepherd moons push the rings debris into an orbit.

An example of Saturn’s Shepherd Moons.

Chaotic Orbits

The gravity of the inner moons causes them to pull on each other, making their orbits unstable. Scientists created simulations that show all the moons future orbits. They found out that the moons will either switch places or crash into one another!
 

All the Inner Moons

A list of all of Uranus’s inner moons from closest to the planet to furthest away. All the moons are named after characters from Shakespeare’s and Alexander Pope’s writings.

CORDELIA

Cordelia, the closest moon to the surface of the planet Uranus.  Voyager 2 discovered Cordelia in 1986.  It appears that this moon’s a shepherd moon for Uranus’ Epsilon ring.  A shepherd moon orbits a planet on the edge of its rings.  By orbiting on the edge of the ring, the moon keeps the dust and ice inside of the ring, much like a shepherd keeps sheep inside a field. In Shakespeare’s play King Lear Cordelia was a daughter of King Lear.

 

OPHELIA

Ophelia is the second of Uranus’ moons.  This world orbits just outside the Epsilon ring, and for this reason is believed to be, like Cordelia, a shepherd moon.

Ophelia, discovered by Voyager 2 in 1986, was named after the daughter of Polonius in Shakespeare’s Hamlet.

 

BIANCA

Voyager 2 discovered Bianca in 1986.  It is a small icy world, and like many of Uranus’ moons, probably a captured asteroid or comet.

Bianca’s named after the sister of Katherine in Shakespeare’s Taming of the Shrew.

 

CRESSIDA

The fourth of Uranus’ moons is the world Cressida.  Voyager 2 discovered Cressida on it’s flyby in 1986.

Cressida is the daughter of Calchas in Shakespeare’s play Troilus and Cressida.

 

DESDEMONA

Discovered in 1986 by Voyager 2, Desdemona is the fifth of Uranus’ moons.

Desdemona is the wife of Othello in Shakespeare’s Othello.

 

JULIET

Juliet is the sixth moon from the surface of Uranus, discovered by Voyager 2 in 1986.

This moon’s named after the young girl in Shakespeare’s play Romeo and Juliet.

 

PORTIA

Uranus’ seventh known moon is the world Portia.  Voyager 2 discovered Portia in 1986.

Portia was a rich woman in Shakespeare’s Merchant of Venice.

 

ROSALIND

Rosalind is the eighth moon from the surface of the planet Uranus.  Voyager 2 discovered this moon in 1986.

Rosalind is a daughter of the banished Duke in Shakespeare’s play As You Like It.

 

BELINDA

Discovered in 1986 by Voyager 2, Belinda is the ninth of Uranus’ moons.

This moon’s named after the heroine in Alexander Pope’s The Rape of the Lock.

 

PUCK

The tenth of Uranus’ moons is Puck.  Voyager 2 discovered Puck in 1986.

Puck is a fairy in Shakespeare’s Midsummer Night’s Dream.

 

Other Moons

There are 3 other moons, all of which are smaller and less well-known. 

  • Cupid
  • Perdita
  • Mab

Other Great Resources:

Dust Bunny on the Moons of Uranus: http://www.dustbunny.com/afk/planets/uranus/uranusmoons.html

Kiddle on the Moons of Uranus: https://kids.kiddle.co/List_of_Uranus%27_moons

Planetary on the Moons of Uranus: http://www.planetary.org/multimedia/space-images/uranus/voyager2_uranus_moons_color_stryk.html

Space.com on the Moons of Uranus: https://www.space.com/22201-uranus-moons.html

Written by: Sabryne Fattouh