5. Formation of the Solar System

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.

Topics:

Cloud collapse
Angular momentum
Protoplanets
Differentiation
Gas accretion
Impacts

Reading:


Ch. 3	FORMATION OF THE SOLAR SYSTEM (p. 66)
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:

The Nine Planets
Extensive pages on the Solar System, by Bill Arnett.
Views of the Solar System
Multimedia web pages on the Solar System, by Calvin J. Hamilton.
Overview Of The Solar System
A summary of the Solar System, describing the properties of the major planets as well as the contents of assorted belts of rubble.
Origin of the Solar System (3.4 Mbyte avi animation).
Clip of the NASA movie I Will See Such Things, from web site http://spaceart.com .
Cloud collapse: face-on and edge-on (2.4 Mbyte mpegs)
Computer simulations of a cloud of gas collapsing to a thin rotating disk. Seperate views face-on and edge-on to the disk are shown. Color indicates gas density, with blue for the lowest densities and red for the highest densities.
Collision (1.1 Mbyte mpeg)
Collision and merger of two gas giants, shown here to illustrate the rotation of the end-product.
Formation of the Moon
Computer simulations of impact leading to the formation of the Moon. See this animation (2.9 Mbyte .mov file).

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
http://www.ifa.hawaii.edu/~barnes/ast110/fotss.html