The History of Earth is the development of the planet where humanity lives. According to scientists is the Earth about 4.56 billion years old (4,560,000,000 years). This age has been determined by measuring radioactive decay, a very complicated but precise way to measure how old something is. The universe itself was created 13.8 billion years ago, by the big bang. So that's three times older than the Earth. The history of the Earth is divided into parts on the geologic time scale. This scale consists of four eons, all of which are divided. The eras on this scale are based on life on Earth, the atmosphere, ice ages, earthquakes and volcanic eruptions, and building the Earth's crust and Earth core. We are currently in the Holocene, an era that started after the final ice age and now 11,700 years.
