Notes # 1 Formation of the

Solar System

Be able to explain the evidence

used to describe the formation and

early history of Earth.

1. The solar system formed from a

rotating cloud of dust and gas called a

nebula that condensed due to gravity.

How do we know the

nebula was spinning?

Spinning caused the

solar system to flatten

into a plane

1. The solar system formed from a rotating cloud

of dust and gas called a nebula that condensed

due to gravity.

In the center of the solar system a very dense

concentration of gas formed called a protostar

2. While a protostar formed in the

center of the solar system planets

formed in the disk.

Planetesimals (planet forming

chunks of rock) formed as

matter condensed around the

rotating disk

When nuclear fusion began,

heat from the sun causes

gases with low melting

temperatures to be pushed out

into the outer parts of the solar

system where they become

gassy planetesimals

2. While a protostar formed in the

center of the solar system planets

formed in the disk.

Near the sun, rocky planetesimals grew into rocky

protoplanets

Farther from the sun, gassy protoplanets formed

Some planetessimals do not collect in the planets

and are leftover: asteroids, comets

3. Observations of the solar system

provide evidence for Earth’s early

formation history. Craters on planets like Mercury

show that the planets were bombarded early in the formation of the solar system

Planets like Earth and Mars have few craters because the surface was changed by erosion; shows the bombardment ended long ago

The solar system formed all at the same time so the age of Earth (4.6 billion years) is determined from the age of other solar system objects

Video if wanted

https://www.youtube.com/watch?v=TKM

0P3XlMNA&list=PL8dPuuaLjXtPAJr1ys

d5yGIyiSFuh0mIL&index=9

Start at 5:30