Study Guide for Exam 2

Listed below are some items to consider when studying for the second exam. This should not be regarded as an exhaustive list, and you should combine this with general chapter reviews, review of your homeworks, and your own judgement.

Chapter 6 & 15 - The Solar System - Properties and Origin

• Be able to list planets in order of distance from sun.
• Be able to classify as terrestrial or jovian.
• Be able to list characteristics of terrestrial / jovian planets.
• Be able fill in the following table of general solar system properties:
  

  Property	Meaning	Explanation from Solar System Formation
  SS is Flat
  SS is Right Handed or Counterclockwise
  Planets in isolated, nearly circular orbits
  Inner planets are terrestrial, outer planets are jovian.
  Metals decrease with distance from sun.

• For individual planet characteristics, should know the following:
  • Mercury - Closest to sun; no atmosphere; heavily cratered; relatively large metallic core; largest temperature swings.
  • Venus - Highest surface temperature due to extreme greenhouse effect; thick carbon dioxide atmosphere; slow retrograde rotation; size and mass very similar to Earth.
  • Earth - Only planet with liquid water; only planet with life; predominantly nitrogen atmosphere; moderate greenhouse effect increases average surface temp by 10-20 degrees C.
  • Mars - Thin carbon dioxide atmosphere; axial tilt and rotation period very similar to Earth; frozen carbon dioxide polar caps; evidence of past surface water.
  • Jupiter - Largest planet in solar system; composition mostly hydrogen and helium; liquid metallic hydrogen interior; large magnetic field; surface coloration due to persistent weather patterns and storms.
  • Saturn - Extensive ring system; composition mostly hydrogen and helium; liquid metallic hydrogen interior.
  • Uranus - Rotates "on side"; composition mostly hydrogen and helium; non-centered magnetic field due to ionic slush interior.
  • Neptune - Composition mostly hydrogen and helium; non-centered magnetic field due to ionic slush interior.
• Interplanetary debris:
  • For moons - Can be as large as planets; can be rocky or icy; exhibit many of the same features commonly associated with planets, including atmospheres, volcanism, and possibly liquid water.
  • Asteroids - rocky or metallic; mostly located in asteroid belt; date from early nebula.
  • Comets - icy composition; Kuiper belt vs. Oort cloud; date from early nebula.

Chapter 16

• The composition of the sun. (You do not need to know the exact percentages, but you should know the two most abundant elements. Also, how we know this (remember chapters 3 & 4).
• The surface and core temperatures of the sun (and how we know them).
• How old is the sun and how long will it last.
• The layers of the sun, including where the important processes occur.
  • Where is the energy generated?
  • Where does most of the light come from?
  • What layer is responsible for the continuous (Planck, black body) part of the spectrum?
  • What layer is responsible for the absorption lines in the spectrum?
  • Where does the solar wind come from?
• The mechanism by which the sun generates energy.
  • What is the meaning of Einstein's famous equation, E=mc²?
• Note: With the exception of the surface and core temperatures, you do not need to memorize numbers (mass, radius, luminosity, etc).

Chapter 17

• The spectral classes.
  • Be able to list them in order from hottest to coldest.
  • Know how size, mass, and luminosity vary with spectral class for main sequence stars. Be able to tell, if given spectral classes, which star will be hotter/brighter/heavier/larger and which will live longer.
  • Know the specific spectral class of the sun.
• The H-R diagram.
  • Be able to identify the main sequence, red giant, and and white dwarf regions.
  • If given two stars on an H-R diagram, be able to tell which is hotter/brighter/larger. Know when you can and cannot tell which is heavier.
  • Know where the sun appears on an H-R diagram.
• Understand the difficulties of directly measuring various parameters (distance, motion, absolute luminosity, mass) associated with stars.
  • Know the meaning of parallax and spectroscopic parallax, how they differ, and for which stars each can be determined?