SS formation Flashcards
What happened at 0 years
Big bang, rapid wxpansion and cooling of the universe. The universe was hot and dense, a primordial fireball. Only neutrons protons and electrons existed.
What happened After radiation era
375,000 years
CMB makes it cool enough for electrons to become trapped around nuceli.
What happened in Matter era 400 million years
Stars form
What happened at 1.8 billion years
Gravity slows expansion. Stars galaxies planets
What was the solar nebula
A condensing cloud of interstella gas and dust in a spiral arm of the milky way
When was the ss formed
4.6 billion years ago
What did the supernova shockwave do
- collapse the solar nebula under its own gas
- heat and vapurise dust
- create protostar
What happened when the sun was formed
Forces prevented some dust from being pulled to the core. This dust formed the accretion disk
What happened to the tiny ice, rock, metal patricles in the accretion disk
They collided to form asteroids. Gravitational forces pulled asteroids together, forming planetismals. Gravitational attraction formed protoplantes.
Why are commets important to early earth evolution
Some carried variaties of organic molecules and water
Why are meteorites important
Meterorites are made from the same materials from which the earth was formed (aolar nebula dust). Iron meteorites have a smiliar composition to the earths core
Early earth had
Oceans clouds and rain. Crystals formed in molten granite and cooled due to water
The two eras
Hadean and archean.
Why did earths layers begin to seperate?
Varying densities. Densest sunk to bottom, least dense to top.
Layers
Crust, lithosphere, asthenosphere, lower mantle, inner core outer core
