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Period: 4500 BCE to 4500 BCE
Creation of Earth--Planetary Accretion
Tiny star dust/rocks in the solar system attract each other due to their own gravities. As larger rocks are formed, it attract small rocks and eventually becomes the very beginning state of Earth. -
Period: 4500 BCE to 4500 BCE
Formation of the Moon
There are different theories of how the moon was formed, but the mostly accepted theory is that a meteoroid with the size of Mars clashes to the Earth's surface due to Earth's gravitational force, and the debris of that meteoroid forms later on what we call Moon that orbits around the Earth. -
Period: 4000 BCE to 3800 BCE
End of Heavy Bombardment
The late heavy bombardment is believed to be the interval of 20 to 200 million years of meteoroids constantly crashing on to Earth's surface. Less than 25% of Earth's crust would have melted due to the heat created by collisions. Although the temperature on Earth does not seem to be best for living, researchers believe that microbes thrive underneath the Earth's crust, bearing a temperature of 175 to 230 Fahrenheit. -
Period: 4000 BCE to 3600 BCE
Planetary Cooling
At first, Earth was a ball of molten rock. The meteoroids that "attacked" the earth make earth into a pool of melting lava, also known as the period of bombardment. As Earth took millions of years to cool, the radioactivity in the core kept the Earth warm. As the Earth's crust formed due to cooling, constant convection in the mantle also help Earth lose heat -
Period: 1500 BCE to 1000 BCE
Core Formation
The Earth’s inner core formed approximately 1.5 billion years ago, when there is a sudden increase of magnetic field. This is said to cause the occurrence of solid iron in the Earth’s core. According to Science Daily, “the Earth’s magnetic field is generated by the motion of liquid iron in the outer core " due to the convection of mantle.