Ch 11+12 Flashcards
Giant Planets Composition
- Gases: hydrogen, helium
- Ices: water, methane, ammonia
- Rocks: magnesium, silicon, iron, etc.
“Gas Giants”
Jupiter + Saturn
“Ice Giants”
Uranus + Neptune
Jupiter Rotation
9 hours 56 minutes, shortest day of any planet due to magnetic field deep inside planet
Jupiter Spin Axis
3 degrees tilt, no seasons
Saturn Spin Axis
27 degrees tilt, does have seasons
Neptune Spin Axis
29 degrees tilt, similar seasons, just more slowly
Uranus Spin Axis
98 degrees tilt north, basically orbits on its side
Jupiter Internal Structure
Rock, Ice, Metallic Hydrogen, Molecular Hydrogen
Saturn Internal Strucure
Rock, Ice, Metallic Hydrogen (less), Molecular Hydrogen
Uranus + Neptune Internal Structure
Rock, Ice, Molecular Hydrogen
Internal Energy of Giant Planets
- Jupiter, most
- Saturn, half of Jupiter
- Neptune, small internal energy source
- Uranus, no measurable amount of internal heat
Jupiter’s Magnetic Field
- Very very strong
- Axis of mag. field is 10 degrees, different from axis of rotation
Voyager 2
Toured all of the outer planets
Direct / Regular Orbits
Roughly 1/3 of moons in outer solar system have these orbits – revolve parent planet west to east in plane of equator
Retrograde
Orbit in east to west direction
High Eccentricity Orbit
More elliptical orbit than circular
High Inclination Orbit
Moving in and out of planet’s equatorial plane
Jupiter’s Moons
67 known moons: Callisto, Ganymede, Europa, Io
Saturn’s Moons
62 known moons: Titan - only moon with substantial atmosphere + lakes or seas of liquid hydrocarbons, Enceladus - active geysers
Saturn’s Rings
Broad + flat with few major and many minor gaps | huge collection of icy fragments
Uranus System
Tilted at 98 degrees; 11 rings, 27 known moons
Neptune Moons
14 known moons: Triton
Uranus + Neptune’s Rings
Narrow + Faint, made of dark materials
Callisto
17 day orbit, keeps same face toward Jupiter - water ice is stable; same size as Mercury
Ganymede
largest moon in solar system; great deal of cratering; fully differentiated; mantle and crust of ice “floating” above rock core
Europa
ice-covered surface; has unusually straight lines on icy crust; might have large ocean of liquid water under its ice
Io
Innermost moon of Jupiter; high level of volcanism (>100); size of Moon; tidal heating
Titan
thick atmosphere of CO, hydrocarbons, methane, ethane, propane; 1.6 bars; lakes, rivers, falling rain
Triton
Neptune’s largest moon; 75% rock, 25% water ice; have impact craters, flooded “lava”, mountainous terrain; nitrogen geysers
Pluto
4 small moons; dwarf planet; different orbit around Sun
Pluto’s Surface
frozen methane, carbon monoxide, nitrogen
New Horizons
2006, spacecraft that observed Pluto
Charon
Pluto’s Moon; half Pluto’s size; Charon + Pluto keep same sides to each other
Breakup Hypothesis
Rings are the remains of a shattered moon, tidal forces pulled the fragments apart, and they dispersed into a disk
Secondary Ring Hypothesis
Suggests rings are made of particles that were unable to come together to form a moon
Saturn Ring Names
outer>inner, A, B, C with B being the brightest
Cassini Division
Wide gap between A and B Rings in Saturn
Occultation
Passage of one astronomical object in front of another
Epsilon Ring
Outermost & Most massive of Uranus’ rings; twice radius of Uranus
Resonance
When two objects have orbital periods that are exact rations of each other
F Ring
Saturn’s narrow ring that contains apparent ringlets
