GEOS 1004 Lecture Notes - Lecture 1: Outer Core, Inner Core, Big Bang
Document Summary
All matter in the universe, including our solar system, was originally ejected from the big bang. The very light elements hydrogen and helium formed the first stars and galaxies. Nuclear fusion within stars formed heavier elements capable of bonding into more complex molecules (very important!) Material in the solar nebula came from ________dead stars composed of dust grains and gas____________. Contraction of solar nebula began around 5 billion years ago. Contraction led to temperature increase and breakdown of dust particles in the solar nebula. Rocky planets formed from the solar nebula, which were clumps of rocky and metallic debris. Collisions between debris planetesimals caused a second heating event that distilled light elements towards the outer parts of the solar nebula. High density (material property) explains why rocky planets are close to the sun and gas planets are farther away. Bombardment by debris and radioactive decay heated early earth to the point of melting entirely.
