The Precambrian

The longest geological period

The Precambrian began about 4.6 billion years ago and ended 543 million years ago. With a duration of almost four billion years, the Precambrian is thus the longest geological time period.

At the beginning of the Precambrian, our solar system consisted of nebulae, dust, rocks, asteroids, and meteorites. These formed the 8 planets of our solar system.

Then, about 4 billion years ago, a planet, the size of Mars, crashed into planet earth.  The violent impact hurled huge chunks of rock into space, creating the moon. The moon ensured that the Earth stabilised its rotation and it contributed to the formation of tides and seasons.

The tides cleansed the Earth's shallow seas, where, soon, perfect conditions arose for the development of life. Stromatolites, the oldest verifiable fossils, dominated these shallow seas for millions of years. 

They were microorganisms and responsible for the formation of oxygen on earth. When an excess of oxygen eventually accumulated in the sea, it was released into the air, slowly forming an atmosphere, and allowing more complex life forms to evolve on Earth.