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The first eon in Earth's history, the Hadean, begins with the Earth's formation and is followed by the Archean eon at 3.8 Ga.: 145 The oldest rocks found on Earth date to about 4.0 Ga, and the oldest detrital zircon crystals in rocks to about 4.4 Ga, soon after the formation of the Earth's crust and the Earth
The geological history of the Earth follows the major geological events in Earth's past based on the geological time scale, a system of chronological measurement based on the study of the planet's rock layers ( stratigraphy ). Earth formed about 4.54 billion years ago by accretion from the solar nebula, a disk-shaped mass of dust and gas left ...
c. 4,300 Ma – Nectarian Era begins on Earth. c. 4,250 Ma – Earliest evidence for life, based on unusually high amounts of light isotopes of carbon, a common sign of life, found in Earth's oldest mineral deposits located in the Jack Hills of Western Australia. [4] c. 4,100 Ma – Early Imbrian Era begins on Earth.
These timelines of world history detail recorded events since the creation of writing roughly 5000 years ago to the present day. For events from c. 3200 BC – c. 500 see: Timeline of ancient history. For events from c. 500 – c. 1499, see: Timeline of post-classical history. For events from c. 1500, see: Timelines of modern history.
The geologic time scale is a way of representing deep time based on events that have occurred throughout Earth's history, a time span of about 4.54 ± 0.05 Ga (4.54 billion years). [5] It chronologically organises strata, and subsequently time, by observing fundamental changes in stratigraphy that correspond to major geological or ...
History. According to evidence from radiometric dating and other sources, Earth formed about 4.54 billion years ago. The current dominant theory of planet formation suggests that planets such as Earth form in about 50 to 100 million years but more recently proposed alternative processes and timescales have stimulated ongoing debate in the planetary science community.
In 1862, the physicist William Thomson, 1st Baron Kelvin published calculations that fixed the age of Earth at between 20 million and 400 million years. He assumed that Earth had formed as a completely molten object, and determined the amount of time it would take for the near-surface temperature gradient to decrease to its present value.
First image taken of Earth from the surface of Mars and any celestial body other than the Moon. July 27, 2006 Cassini-Huygens: The Pale Blue Orb is the first image of Earth from Saturn. October 8, 2014 MESSENGER: The first image of Earth's shadow causing a lunar eclipse from another planet.