5. Formation of the Solar System

Last: 4. Revolution of the Spheres Next: 6. The Inner Planets

The Solar System formed when a cold, slowly-rotating cloud of gas and dust collapsed because of its own gravity about 4.5 billion years ago. As the Sun grew hot enough to ignite the nuclear reactions which sustain it today, it vaporized the cold ices and frozen gasses in the inner solar system, leaving behind the rocky dust and metals which form the inner planets. The outer Solar System remained cold, and the ices and gas there collected into the giant outer planets.

The problem with this scenario is that we now have observations of planetary systems around other stars -- and few if any of them resemble our Solar System.



    Ch. 3-7 The solar system formed from a cloud of cold gas and dust
    Ch. 3-8 Gravity and heat shaped the young solar system
    Ch. 3-9 Innumerable collisions occurred in the early solar system
    Ch. 3-10 Comparisons among the nine planets show distinct similarities and significant differences
    Ch. 3-11 Minor debris from the formation of the solar system still exists
    Ch. 3-12 Planets have been discovered outside the solar system

Web Resources:

Homework 5: Using Kepler's Laws, due 10/02.

Quiz 5: Architecture of the Solar System, given 9/27.

Joshua E. Barnes (barnes@ifa.hawaii.edu)

Last modified: September 27, 2001