Earth formed 4.6 billion years ago. At first our solar system was very violent, with matter colliding and forming bigger orbiting rocks. Eventually Earth formed from enough collisions.
Heavy Bombardment Ends
This event took place 4.5 billion years ago. Scientists think that it formed when a planet the size of Mars crashed into the Earth, and the debris formed the moon.
Oldest Stromatolites Form
The early earth was not sustainable to humans today, in fact, the earliest life (which formed 4 billion years ago), were very tough. They survived in places that could kill humans in instants, like caves filled with toxic gases.
First Supercontinent Forms
The heavy bombardment was the time when asteroids kept colliding with Earth. This is because the solar system was still forming, and there were still some planets not yet formed. It ended 3.9 billion years ago.
Stromatolites look like big rocks in shallow water. But they are formed by thin layers (fossils of) cyanobacteria. The oldest ones formed 3.5 billion years ago.
The first supercontinent is called Supercontinent Ur, which formed 3 billion years ago.