Outer Worlds; Rings and ancient worlds

Question 1

What are the type/characteristics of giant planet satellites?

Answer 1

Regular Satellites; large, moon sized, formed by co-accretion, low eccentricity & low inclination, close to planet, prograde orbit, same face towards parent planet

Irregular satellites; small, asteroid size, formed by capture, prograde and retrograde orbit, high eccentricity and inclination and far from planet

Rings; very small, prograde, very low eccentricity, very low inclination, very close to planet…influenced by satellites far away and close
Jupiter has tiny ring that is a bunch of thrown off material (jupiter has its own snow line)
Ring gaps occur because resonances with satellites

Question 2

What is the roche limit of a planet?

Answer 2

Inside (Tidal force > gravitational force…smaller size and closer distance…rings)
Outside (Gravitational force > tidal force…larger size and further distance…regular satellite)
gravity = Mm/diameter^2
Rroche = 2.5 Rplanet

Question 3

How are the surfaces of ancient worlds similar/different from the Earths moon?

Answer 3

Similar size, mass, albedo
Different crater population and density- ancient worlds are crater saturated (new impacts destroy craters as fast as they make new ones…number in crater density doesn’t change)

Cant tell ages because the difference in crater pop (lots more smaller craters).

Has fractures and grooved surfaces (plate tectonics) meaning a younger surface…similar to moon

Geological activity;
Inner- begin molten from melting ice then cools and cannot melt rock now
Outer- Werent hot enough to melt ice but are still geologically active because it takes little energy to change the surface

Question 4

Iapetus

Answer 4

outermost regular satellite

Varies in albedo - has a dark side (leading) and bright side

Material thrown off of phoebe (satellite) is collected on dark side…Tholin makes it dark

Question 5

Source of impactors theory

Answer 5

Inner; asteroid belt

Outer; kuiper belt