Origin Of The Solar System

 

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I) Origin of the Solar System

A) Creation by Supreme Being

B) Solar Nebula Theory

1) 4.5 billion years ago

2) Formed from a spinning ball of gas and dust

3) Sun became luminous

4) Remaining dust and gas were blown into space by solar wind

II) Formation of Solar System

A) Planets move around the Sun in orbits that lie in a common plane

1) Revolve in same direction

2) Process of condensation

(a) Heavier elements condensed toward the hotter, inner part of the nebula

(b) Lighter, more volatile elements condensed further out

3) Planetisimals formed

(a) Inner collected heavier material

(b) Outer collected lighter material

(c) Growing larger, acted as “vacuum cleaners” ridding the solar system of debris

(1) Two types of planets formed

(i) Terrestrial

1. Earth-like

a. Small, dense, rocky

2. Mercury, Venus, Earth and Mars

(ii) Jovian       

1. Jupiter-like

a. Enormous gas giants, less dense and cold

b. Jupiter, Saturn, Uranus, Neptune

4) Solar system is left now with three types of debris from the solar nebula

(a) Asteroids

(1) Small, rocky worlds

(2) Asteroid belt between Mars and Jupiter

(i) Remains of an unformed planet

(b) Comets

(1) Dirty snowball

(2) Three parts

(i) Nucleus

1. Frozen water and carbon dioxide

(ii) Coma

1. Bright area surrounding the nucleus

(iii) Tail

1. Luminous trail of debris

2. Trails away from Sun due to solar wind

(3) Originates from Oort Cloud or Kuiper Belt

(c) Meteoroids

(1) Space object – rock, sand, etc.

(i) Meteoroid (in space)

(ii) Meteor (in atmosphere)

(iii) Meteorite (land on planet)

 

Meteorite Types & Percentage that Falls to the Earth

  • Stony meteorites

    • Chondrites (85.7%)
      • Carbonaceous

      • Enstatite

    • Achondrites (7.1%)

      • HED group

      • SNC group

      • Aubrites

      • Ureilites

  • Stony iron meteorites (1.5%)

    • Pallasites
    • Mesosiderites
  • Iron meteorites (5.7%)

 

Comets

Comets are small, fragile, irregularly shaped bodies composed of a mixture of non-volatile grains and frozen gases.  They have highly elliptical orbits that bring them very close to the Sun and swing them deeply into space, often beyond the orbit of Pluto.  As comets approach the Sun, they develop long  enormous tails of luminous material that extend for millions of kilometers from the head, away from the Sun.  This material is being melted and blown off into space by the Sun and the solar wind.

Each time a comet visits the Sun, it loses some of its material.  Eventually, it becomes another rocky mass in the solar system. For this reason, comets are thought to be short-lived, on a cosmological time scale. Many scientists now believe that some asteroids are extinct comet nuclei.

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