Astro 120: Fall 2017
Review Sheet 2
Exam 2 is the evening of November 7
Part II: The Contents of our Solar System
- Rocket Science - transfer orbits and gravitational assist
Observed properties of our Solar System
- density of the planets (Mass/Volume) and what this tells you
about the materials that make up a planet or Moon.
- Dynamical properties (orbits, inclination of spin-axis [obliquity],
- the order of the planets in increasing distance from the Sun
(Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and
- inner "rocky" planets and outer "gas-ball" planets.
Planetary Guts: What is inside a planet?
- mass and radius to determine DENSITY
- mean density vs. surface density
- direct sampling of rock from surface (Earth/Moon, Mars, Venus)
- seismic data from planet quakes to get info about STRUCTURE of
- magnetic fields provide evidence of metallic conducting cores.
- shape and rotation provides data about the PLASTICITY of the
planet or Moon.
Outer Skins of Planets and Moons
- main processes for modification of surfaces:
- impact cratering
- surface atmospheric and chemical weathering
- Know which processes are important on what major objects in the solar
- relative ages of planetary surfaces via crater density
- absolutae ages of planetary surfaces via radioisotope dating
- the impact history of the inner solar system via lunar data
- how are the properties of the moons of the outer planets controlled
- what similarities are there with the inner rocky planets
- Actual atmospheric composition of the atmospheres of the major planets
- The absence of an atmosphere on the Moon and Mercury
- Inventory of carbon dioxide (CO2), nitrogen
and water (H2O), on Venus, Earth and Mars.
- Origin and change of planetary atmospheres.
- primary vs. secondary atmosphere components
- the pressure and temperature structure of planetary atmospheres,
- "greenhouse" effect on Earth and Venus.
- greenhouse effect contributing species: CO2, etc.
- why Venus?
- global warming and climate change on Earth
- How are the activities of human beings changing the balance
and how significant is it?
- Where did the oxygen (O2) come from on Earth and when?
- Ozone depletion and the damaging effects of UV sunlight.
- What factors cause an increase in ozone depletion.
The Inner Planets
- orbit and rotation
- cratering, scarps, and the Caloris basin
- similarities and differences in comparsion with the Moon and
- young surface, volcanism
- few impact craters
- influence of atmosphere
- a bonanza of new information from MER program
- evidence for liquid water in the past
- tectonic, volcanic, and impact features
- comparisons with the Earth
The Outer Planets
- pressure, temperatures strucutres of the outer planets, and their
- differences between the belts and zones of Jupiter
- levels of clouds of different composition and color
- belts, zones, and storms
- Differences between Jupiter and Saturn
- Interior structure (liquid metallic hydrogen) in Jupiter and Saturn.
- difference between Jupiter/Saturn and Uranus/Neptune
Tides and Rings
- the nature of tides and why they occur in Earth
- effects of tides on shape, rotation, and orbit of moons and planets
- effect on the inner moons of the giant planets
(especially Io in the Jupiter system).
- rings of the outer gaseous planets and their composition and
- why they occur within the Roche limit of a typical moon.
Moons of the planets - and beyond
- types and origins
- factors influencing their surfaces.
- ice geology and the effect of tidal stretching
- evidence of subsurface oceans and interior compostion
- volcanic activity on Io and Triton
- the atmosphere of Titan (Saturn's giant moon)
- moon orbits and capture
- Pluto - surprises from New Horizons
- 'Kuiper Belt Objects' and the large icy worlds of the outer solar
- asteroids, meteors and meteorites: what they are
- asteroid belt and Earth-crossing asteroids
- comets and meteor showers
- chemical makeup of meteorites (stones, irons, stoney-irons)
- chondrites, chondules, achondrites, carbonaceous chondrites...
- what meteorites tell us about the early solar system
- meteorites and their relationship to asteriods
- The structure of the cometary nucleus and its immediate surroundings.
- The coma of a comet and what its made of.
- The formation and nature of the ion (plasma) and dust tails of
- Short period comets and long period comets.
- Periodic and nonperiodic comets.
- The origin of comets in the Oort cloud and Kuiper belt.
- Famous comets (Halley and Encke's comet).
- Clues to the formation of the solar system.