Uranus

1
Uranus

• Discovered by William Herschel on March 13th,
  1781
• Named after the ancient god of the sky (Greek
  mythology)
• Tipped on its side -- extreme seasons!

2
Uranus The ringed planet, take II

• http//solarsystem.nasa.gov/multimedia/gallery/PIA
  01278.jpg

3
Uranus

• Chapter 24, section 1
• pages 588 - 603

4
Uranus

• Past missions Voyager 2
• Present missions None
• Future missions None

5
Uranus

• Rotational period (day?) 17h14m
• Orbital period (year?) 84 years
• Average distance from the sun 19.2 AU
• Average diameter 46940km (3.7 D?)

6
Uranuss layers

• Core -- small, heavy element core
• Mantle -- ices of H2O, methane and ammonia, with
  H silicate matter
• Atmosphere -- H He
• Magnetosphere -- weird
• Rings -- faint dark
• Moons -- 27

7
Uranus Magnetosphere

• Very odd indeed!
• 75 as strong as Earths
• Magnetic field is tipped 60o from the axis of
  rotation
• Offset from the centre of the planet (about 30
  of the way to the surface)
• Dynamo effect produced by layer of liquid
  water/ammonia/methane?

8
Uranus Rings

• Discovered in 1977 (occultation)
• Very odd indeed!
• Both planet and rings are tipped!
• Inside the Roche limit

9
Uranus Moons

• 27 at last count, five major moons (Oberon,
  Titania, Umbriel, Ariel Miranda)
• Named after Shakespearean characters
• "Well shone, Moon," wrote Shakespeare, "truly,
  the moon shines with a good grace."

10
Uranus Moons

• http//upload.wikimedia.org/wikipedia/en/6/6f/Uran
  ian_moon_montage.jpg

11
Uranus Tip

• Quite a scientific question!
• http//www.planetary.org/blog/article/00000553/
• http//www.nature.com/nature/journal/v440/n7088/ab
  s/nature04577.html

12
Next up

• Neptune
• Chapter 24, section 2
• Pages 588 - 603