History of Earth

Planetary Accretion

1 CE

(Approx 4.6 billion years ago)
At this time our solar system was just a cloud
of dust and gas, known as a solar
nebula. Gravity collapsed said dust and gas inwards on itself as it began to spin, forming the sun in the
center of the nebula.

Core Formation

2

There have been many estimates for when the earth's inner core was formed, but scientists have used new data which indicates that the Earth's inner core was formed 1-1.5 billion years ago as it 'froze' from the surrounding molten iron outer core. The inner core is Earth's deepest layer. It is a ball of solid iron just larger than Pluto which is surrounded by a liquid outer core

Formation of Moon

3

Approx 4.5 billion years ago, Earths moon
formed from the nearby debris
from a collision between the earth
and an astronomical body the size
of Mars.

Planetary Cooling

4

Approx 3.7 - 4.3 billion years ago, the earth became solid. Every year the earth becomes 100 degrees centigrade cooler.

End of Heavy Bombardment

5

Approx 4.1-3.8 billion years ago
a large amount of
asteroids impacted the terrestrial
planets (including earth)
This completed the accretion
process.