ASTRONOMY 120
Fall 2003 Review Sheet
 
THE SKY AND THE SOLAR SYSTEM(s)
 
   Exam 2 is November 13 at 6:30pm
 

Part II: The Contents of our Solar System


Observed properties of our Solar System

The observed properties of the Solar system. Scale and distribution of matter, t he 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], rotational properties). How evolved are the surfaces of the planets? How "primitive" are they? How do we know their relative ages? Their absolute ages? Have the primitive features been removed by recent activity. Know the order of the planets in increasing distance from the Sun (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto.). Be able to recognize which planet is which by its appearance. Know which are inner "rocky" planets and which are the outer "gas-ball" planets.  


Planetary Guts: What is inside a planet?

What is inside of a planet or moon? How can we tell?. What methods of observations provide info on the interiors of planets? Use Mass and radius to determine DENSITY. Mass determined from Kepler's laws of planet has a moon or change in orbit of passing space probe. Use direct sampling of rock from surface (Earth/Moon, Mars, Venus) to determine (INDIRECTLY) what the insides may contain CHEMICALLY. Use seismic data from planet quakes to get info about STRUCTURE of interiors. 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

Know what factors modify the surfaces of planets or Moons. Understand the four main processes: impact cratering, volcanism, tectonics, surface atmospheric and chemical weathering. Know which processes are important on what major objects in the solar system. How are the properties of the moons of the outer planets controlled and what similarities are there with the inner rocky planets?  


Planetary Atmospheres

Actual atmospheric composition of the atmospheres of the major planets, especially Venus, Earth, Mars and the outer gas-ball planets. The absence of an atmosphere on the Moon and Mercury. Inventory of carbon dioxide (CO2), nitrogen (N2), and water (H2O), on Venus, Earth and Mars. Origin and change of planetary atmospheres.

An understanding of "greenhouse" effect on Earth and Venus. Where did the oxygen (O2) come from on Earth and when? What gasses contribute to global warming on Earth? What factors contribute to global warmoing? How are the activities of human beings changing the balance and how significant is it? What can be done about it? The damaging effects of UV sunlight. What factors cause an increase in ozone depletion.  


The Outer Planets

The structure of the outer planets and what we know about there cloud structures including the Giant Red Spot of Jupiter. The temperature, pressure and composition of the outer planets and the principal forms of clouds present. Differences between the belts and zones of Jupiter. Levels of clouds of different composition and color. Differences between Jupiter, Saturn, and the other gas-balls. Interior structure (liquid metallic hydrogen) in Jupiter and Saturn.

Moons of the outer planets - 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). Etc..  


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. The effect on the inner moons of the giant planets (especially Io in the Jupiter system). The rings of the outer gaseous planets and their composition and structure. Why they occur within the tidal radius of a typical moon. Why the Earth does not have a major ring system.


Small Bodies

Meteors and Meteorites: what they are. Comets and meteor showers. The chemical makeup of meteorites (stones, irons, stoney-Irons), Chondrites, chondules, achondrites, carbonaceous chondrites... What meteorites tell us about the early solar system. Age of meteoroids and their relationship with the asteroid belt and Earth-crossing asteroids, based on an analysis of their orbits and their composition.


Impacts!

Impact record of the Moon compared with the inner planets. Terrestrial impacts. The impact hazard scale: small impacts are more frequent. Crater size related to impactor size (crater 10x larger than impactor). Effects of large impacts on life on Earth. Extinction of the dinosaurs: evidence of an impact causing it. Other sample impacts: Arizona meteor crater, Tunguska, Comet SL9 and Jupiter.