-
46,000 BCE
Core formation of the Earth
Earth formed 4.6 billion years ago, through the accretion of planetary embryos and planetesimals. The energy delivered by progressively larger impactors maintained Earth’s outer layer as an extensively molten magma ocean. Gravitational segregation of metal and silicate within the magma ocean resulted in the primary differentiation of the planet characterized by a metallic core and silicate mantle. -
46,000 BCE
Planetary Acceration
The formation and evolution of the Solar System began 4.6 billion years ago with the gravitational collapse of a small part of a giant molecular cloud. Most of the collapsing mass collected in the center, forming the Sun, while the rest flattened into a protoplanetary disk out of which the planets, moons, asteroids, and other small Solar System bodies formed. -
45,000 BCE
The birth of the Moon
There was a lot of space debris. Asteroids flew around, sometimes striking the planets. An asteroid the size of Mars smashed into Earth. The huge amount of energy from the impact melted most of Earth. Material from both Earth and the asteroid was thrown out into orbit. Over time, this material smashed together to form our Moon. The lunar surface of the Moon is about 4.5 billion years old. -
Period: 45,000 BCE to 38,000 BCE
Planetary Cooling
About 4.5 - 3.8 billion planetary cooling formed the planet into a molten planet. Clumps of asteroids, meteors, and comets helped formed the planet into a sphere. There were volcanic eruptions as well which contained magma. The magma then hardened which created Earth's outer core. -
Period: 40,000 BCE to 38,000 BCE
End of Heavy Bombardment
About 4 to 3.8 billion years ago a period of intense comet and asteroid bombardment is thought to have peppered all the planets including the Earth. Many of the numerous craters found on the Moon and other bodies in the Solar System record this event.
