Notes
Outline
Moons of the Outer Planets
The Galilean Moons
The Interiors of the Galilean Moons
Io – the volcanic moon
Volcanoes on Io
Europa
An Internal Ocean on Europa?
Some Moons of Saturn
Miranda – the “messed-up” moon of Uranus
The Rings of Saturn
Rings and the “Roche Limit”
Ring Structures
Jupiter’s Ring
Uranus’ Rings
Neptune’s “Arc” Rings
Asteriods
“Minor planets”, ranging in size from several hundred km to boulders (most less than 10 km)
104 to 105 objects (with 106 to 107 km average separations)
Orbits are fairly circular, most between Mars and Jupiter; some orbits in resonance with Jupiter; some Earth-crossing
Asteroid Orbital Resonances
Production of Asteroids (and meteors)
Visiting the Asteroids
Eros and the NEAR mission
Craters large and small
Landing on an asteroid
Icy Planetesimals : Comets
Parts of a Comet
Bright Comets
Comets can be beautiful
Meteor Showers : Remnant Comets
The Leonid Meteor Shower
Meteors and Meteorites
Types of Meteors
“Carbonaceous”: lighter elements (C, Si, Mg), can be covered with dark organic compounds or rocky material
Source: unformed planet or planetesimal
“Metallic”: dominantly nickel/iron
Source: differentiated body broken up later
“Basaltic”: like lava; must have been melted rock
Source: differentiated body or large collision
Inside Meteorites
The Sources of Meteors and Comets
Sometimes they hit us…
The Shoemaker-Levy Impact
Deep Impact…
It’s a good thing it wasn’t us…
The Dinosaurs weren’t so lucky…
Boom!!!!
How likely is it?
The end of all surface life on the Earth