Uranus

1
Uranus
Discovered in 1781 by William Herschel The muse
of Astronomy and father of Saturn Visible to the
naked eye (barely) Observations from the Earth
reveal tilted on side has a ring system
2
Uranus visited by Voyager 2 in 1986
3
Voyager 2 did not see any cloud features -
why? Uranus has no internal heat!
4
Wait a minute! Now we do see clouds on
Uranus! Whats happening? Seasonal variations!
5
Rock
Compressed water, methane, ammonia ocean
Liquid H, He
Magnetic field is tilted and off axis
6
Rings
7
Uranus Satellites - 27
8
Names

• Cordelia
• Ophelia
• Bianca
• Cressida
• Desdemona
• Juliet, Mab
• Portia
• Rosalind
• Margaret
• Perdita
• Cupid
• Puck, Titania, Oberon
• Miranda, Ariel, Caliban, Sycorax, Prospero,
  Setebos, Stephano,Trinculo, Francisco, Ferdinand

• King Lear
• Hamlet
• Taming of the Shrew
• Troilus and Cressida
• Othello
• Romeo and Juliet (Duh!)
• Merchant of Venice
• As You Like it
• Much Ado About Nothing
• The Winters Tale
• Timon of Athens
• Midsummer-Nights Dream
• The Tempest

9
Small, icy worlds
10
Miranda - The Fractured Moon
11
Huge Cliff!
12
Strange patterns Discoloration Why?
13
Neptune
1846 - An Englishman, a Frenchman and a German
John Couch Adams
Urbain Le Verrier
Johann Galle
Co-discoverers
14
Voyager 2 flew by in August 1989
Similar to Uranus Same composition Similar mass,
radius Similar cloud structures Similar magnetic
fields (off axis, off center) More active
atmosphere
15
(No Transcript)
16
Great Dark Spot Analogous to the Great Red Spot
17
1998
2005
No Great Dark Spot (Guess it wasnt so
great!) Other spots seen - seasonal variations
18
Rings
Ring Arcs
19
Neptunes Moons
13 known satellites Small icy worlds Heavily
cratered
20
Triton - The Geyser World
21
Geysers that erupt gas (nitrogen and methane) and
ice (mainly methane ice) Tritons unusual orbit
- tidal heated
22
Beyond Neptune...
1930 - Pluto Discovered 1951 - Kuiper Belt
proposed 1992 - Discovery of another object
beyond Neptune Kuiper Belt Objects Trans-Neptun
ian Objects 1,000 known (so far), 100,000 may
exist 30 - few hundred AU
23
(No Transcript)
24
Pluto
The only planet not to be visited by a
spacecraft Discovered in 1930 by Clyde
Tombaugh Moon (Charon) discovered in 1978 by
Robert Christy 2 more satellites recently
discovered (2005)
25
Observations of Pluto
Small, icy Has an atmosphere sometimes
26
(No Transcript)
27
Is it a planet?
28
2003 UB313
Bigger than Pluto! Has a satellite Is this a
planet? What about Sedna?
29
What about the other KBOs? Are they planets?