•Why do different planets have different
levels of geologic activity?
•
•Why do different planets have different
atmospheres?
•
•What are ages of old
“unaltered” planetary surfaces?
–Should be similar, and agree roughly with
age of Sun
–
•Does composition of asteroids match
predictions?
–Lower temperature than Mars region: Hydrated silicates, etc.
•
•What types of minerals do we see in
meteorites?
•
•What types of ices and minerals do we see
in comets?