GEOL 3045: Planetary Geology

Lysa ChizmadiaUranus’ Moons

Introduction 27 named moons

– Named after Shakesperian & Alexander Pope characters

Groups– Shepherding Moons– Chaotic Moon Swarm– Puck, Mab & Cupid– Large Inner Satellites– Outer Irregular Satellites

Image from: http://solarsystem.nasa.gov/planets/profile.cfm?Display=Moons&Object=Uranus

Shepherding Moons Keep outer epsilon ring well

defined Cordelia

– Inner shepherd– 15km in diameter

Ophelia– Outer shepherd– 16 km in diameter

Must be inner shepherds, but not yet discovered

Image from: http://solarsystem.nasa.gov/planets/profile.cfm?Object=Ura_Cordelia

Choatic Moon Swarm Orbital parameters highly chaotic

– Probably collide with each other regularly

8 small satellites– Bianca (21 km radius)– Cressida (33km radius)– Desdemona (27 km radius)– Juliet (42km radius)– Portia (54km radius)– Rosalind (27km radius)– Belinda (33km radius)– Perdita

Images from: http://solarsystem.nasa.gov/planets/profile.cfm?Display=Moons&Object=Uranus

Puck, Mab & Cupid Puck

– 77km radius– Orbital period: 0.76 days– Inclination: 0.31 degrees

Mab– 16 km radius– Orbital period: 0.92 days

Cupid– 12km radius– Orbital period: 0.61 days

Image from: http://www.solarviews.com/eng/puck.htm

Major Satellites Miranda

– Smallest of 5– Huge fault canyons

Ariel– Brightest & very young surface– Intersecting valleys

Umbriel– Darkest & ancient– Mysterious bright ring

Titania– Largest moon

Oberon– Heavily cratered

Image from: http://en.wikipedia.org/wiki/Moons_of_Uranus

Image from: http://www.daviddarling.info/images/Uranus_moons.jpg

Miranda Diameter: 470 km Orbital period: 1.4 days Eccentricity: 0.0013 Inclination: 4.23 (high) Density: 1.20 g/cm3 Fault canyons

– 20km deep Mixture of young & old

terrains– Jumbled together– Tidal forces?

Image from: http://www.daviddarling.info/encyclopedia/U/Uranusmoons.html

Ariel Diameter: 1156 km Orbital period: 2.5 days Eccentricity: 0.0012 Inclination: 0.26 Density: 1.67 g/cm3 Mixture of heavily cratered

terrains & smooth plains Dry ice detected on surface Interconnected valleys

– Chasmata– 100s km long– >10 km deep– Floors smoothed by fluid

Image from: http://www.daviddarling.info/encyclopedia/U/Uranusmoons.html

Umbriel Diameter: 1169 km (~ Ariel) Orbital period: 4.14 days Eccentricity: 0.0039 Inclination: 0.36 Density: 1.40 g/cm3 (~ Ariel) Very old, heavily cratered

surface Mysterious bright ring

– Wunda– 140 km diameter

Image from: http://www.daviddarling.info/encyclopedia/U/Uranusmoons.html

Wunda

Titania Orbital period: 8.7 days Eccentricity: 0.0011 Inclination: 0.34 Density: 1.72 g/cm3 Largest moon of Uranus Mixture of cratered

terrains & interconnected valleys– Largest trench 1600km long– Faults internal forces

Image from: http://www.daviddarling.info/encyclopedia/U/Uranusmoons.html

Image from:http://www.solarviews.com/eng/titania.htm

Oberon Diameter: 1523 km Orbital period: 13.5 days Eccentricity: 0.0008 Inclination: 0.10 Density: 1.64 g/cm3 2nd Largest moon of

Uranus Heavily cratered w/ bright

rays S hemisphere has large

faultsImage from: http://www.daviddarling.info/encyclopedia/U/Uranusmoons.html

6 km high

Outer Irregular Satellites Retrograde & highly

inclined 5 moons

– Caliban– Stephano– Sycorax– Prospero– Setebos

Image from: http://en.wikipedia.org/wiki/Moons_of_Uranus

Image from: http://www.solarviews.com/eng/caliban.htm

Summary Inner shepherd moons

– Cordelia & Ophelia Puck, Mab & Cupid Largest

– Miranda: heavily cratered terrain mixed w/ smooth blocks– Ariel: brightest & has chasmata with smooth floors– Umbriel: darkest & has bright ring crater on N pole– Titania: largest moon & mixture of cratered terrain &

trenchs & faults– Oberon: highly cratered

Outer irregular satellites– Retrograde & highly inclined– Probable captured asteroids