Lecture 15. B. Solar System Overview

Physical Properties: details of particular objects, needed good telescopes and satellites to discover





Dynamical Properties: known for long time -- any massive objects would behave similarly

Titus-Bode rule does predict orbits, & planet at 2.8 AU





Dating:

  1. Cratering: more craters = more impacts = been around to be hit longer
    • assumptions about frequency of hits -- higher long ago?
    • assumptions about removal of evidence of impacts -- weathering, volcanism
  2. Radiation: ratio of Parent & Daughter isotopes (Lect. 11. B.*)
    reveals how long parent has been decaying

















Solar System Formation -- three theories*:

  1. haphazard accumulation -- chance captures of planets/planetesimals
  2. catastrophic origin -- another star collides with Sun,
    gas dragged off forms Jupiter, etc.
  3. solar nebula -- accepted theory
    • initially, a gas cloud
    • gravity causes cloud to collapse
    • conservation of angular momentum causes material to spin (=orbit)
    • gravity flattens along axis of rotation
    • planetesimals accrete
    • VOILA! spins all match, material the same, and same age, etc.
    • for images, check out this great web page!*