The evolution of the Earth from its formation to the present is covered by Earth history.Understanding of the major historical events of Earth's history, which are marked by ongoing geological change and biological development, has been aided by nearly every field of natural science.
According to an international agreement, the geological time scale shows the vast epochs from the Earth's formation to the present, and its divisions document some of the most important moments in Earth history. Ma is interpreted as "million years ago" in the picture. Earth formed by accretion from the solar nebula about 4.54 billion years ago, or about one-third the age of the universe.
The early atmosphere had virtually no oxygen, but it is likely that volcanic outgassing produced the primordial atmosphere and subsequently the ocean. Due to intense volcanism brought on by frequent collisions with other bodies, a large portion of the Earth was molten. The Moon is believed to have formed during the Early Earth period when the Earth had a massive impact collision with Theia, a planet-sized entity. As the Earth cooled throughout time, a solid crust formed and liquid water was able to remain on the surface. Scientists revealed evidence in June 2023 that suggests Earth may have formed in as little as three million years, a significantly shorter time than previously believed (10−100 million years).
The Hadean eon, which started with the planet's genesis and ended 4.0 billion years ago, is the period of time before a trustworthy (fossil) record of life existed. The origins of life on Earth and its initial evolution occurred during the ensuing Archean and Proterozoic ages. The Phanerozoic eon that followed was split into three distinct periods: the Palaeozoic, which included the emergence of arthropods, fish, and land animals; the Mesozoic, which included the development, dominance, and ultimate demise of non-avian dinosaurs; and the Cenozoic, which witnessed the emergence of mammals. At most 2 million years ago, on a geological timescale of vanishingly little, humans as we know them today evolved.
Around 3.5 billion years ago, during the Eoarchean Era, when a geological crust began to develop after the preceding liquid Hadean Eon, the earliest conclusive evidence of life on Earth was discovered. Western Australia's 3.48 billion-year-old sandstone contains microbial mat fossils, such as stromatolites. Graphite, found in metasedimentary rocks 3.7 billion years old located in southwestern Greenland, and "remains of biotic life" found in rocks 4.1 billion years old found in Western Australia provide more early physical evidence of ac Biogen substance. "If life arose relatively quickly on Earth... then it could be common in the universe," stated one of the researchers.
