Final Flashcards
Meteorites
Rocks that fall from the sky (mostly astroid fragments)
Astroids
Rocky bodies that orbit in the inner solar system, most are located in the asteroid belt
How big are largest astroids
few hundered kilometers
Kirkwood gaps
empty areas with no astroids due to jupiter’s ressonances
Meteor
phenomenon of a flash in the sky
Comets parts
Nucleus, coma, ion-tail, plasma tail, hydrogen cloud (be able to draw this
Oort cloud
10^12 comets sent by jupiter (10^4 AU away)
Comet composition
dirty ice or maybe icy dirt
Biggest Kuiper Belt Object?
Pluto – discovered by lowells calculations of the perturbations to neptune’s orbit (but those calculations were in error)
Planetary Rings composed of?
Billions of small particles in orbit around a body.
Why are rings flat?
Collisions dissipate energy and cause the rings to be flat
Optical Depth equation
I = Io exp(-T) where T=n*Pi*a^2*H n = number per vol a = radius (cross section) H = thickness
What is Roche Limit
inside this, planets ties are stronger than gravity holding objects together
Roche limit eq
r
What is found in the roche zone
rings
Ring natural frequencies
mean motion, epicyclic motion, and vertical oscillation
Empty Cylinder Argument
If we have uniformly randomly distributed particles, the probability of volume, V, being empty is a poisson eq
Empty Cylinder Eq
P(o) = exp(-T) where T = nopia^2*H
How do rings and moons interact
Waves sheppard edges, there is possibly recycling between moons and rings
Ring Origins
Moon break-up or frustrated accretion, or comet came to close and broke up
Are rings young or old?
Could be either, maybe young, or maybe recycled
Jupiter Rings
tenuous, dusty
Saturn Rings
broad, thick, made of ice
Uranus Rings
narrow, dark
Neptune Rings
dusty, hyphenated, ring arcs
Planet formation steps (9 steps)
- Giant molecular cloud collapses, fragments
- solar nebula surrounds proto-sun
- solids condense, ices outside of frost line
- grains accrete to form planetesimals
- great collisions reduce planet number
- giand planet cores trap gas
- moons and rings form in mini nebula around planets
- continued accretion and impacts clean up solar system
- solar wind blows away leftover gas
Parallels to planetary rings
- Flat, low temperature
- accretion in both
- Embedded bodies interact with disk: propellers, gaps, density waves
- Angular momentum transfers and cause planet migration (explains ‘hot jupiters’)
- Gian planets may kill smaller ones before star turns on
Temperature Equilibrium Eq
Teq = [ Fo/rau^2 (1-Ab)/(4eps*sig)]^1/4
multiple plate tectonic resurfacing time eq
T = circumference / (number of plates * rate)
Volcanic resurfacing rate equation
R = num of volc * rate / surfarea
Comparitive Planetology
- suffered late heavy bombardment,
- early stage of basaltic volcanism,
- smaller planets have cooled and are now geologically dead.
- Maria indistinguishable (moon, mercury, mars)
- venus, earth were similar when life arose
mafic rocks
more magnesium and iron, denser, more viscous, darker
sialic rocks
lighter, more viscous, brighter
keplers 3 laws
- all planets move in elliptical orbits around the sun
- orbit sweeps out area at a constant rate
- harmonic law p^2 = a^3
Def of planet
orbits the sun, spherical, has cleared the neighborhood around it, orbit
Why is pluto not a planet
- orbit is eccentric an inclined
- small size (2/3 or the moon)
- composition of rock and ice
