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The Hadean (/ h eɪ ˈ d iː ə n, ˈ h eɪ d i ə n / hay-DEE-ən, HAY-dee-ən) is the first and oldest of the four known geologic eons of Earth's history, starting with the planet's formation about 4.6 billion years ago [4] [5] (estimated 4567.30 ± 0.16 million years ago [2] set by the age of the oldest solid material in the Solar System — protoplanetary disk dust particles — found as ...
Ancient Egypt reached the zenith of its power during the New Kingdom (1570–1070 BC) under great pharaohs. Ancient Egypt was a great power to be contended with by both the ancient Near East, the Mediterranean and sub-Saharan Africa. The empire expanded far south into Nubia and held wide territories across the ancient Near East.
In particular, it is sometimes found that the Hadean eon is subdivided into the Cryptic era and Basin Groups 1-9 (which collectively make up the Pre-Nectarian), and the Nectarian and Lower Imbrian. The first lifeforms (self replicating RNA molecules, see RNA world hypothesis) may have evolved on earth around 4 bya during this era.
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. [2]: 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, [34] [35] [36] soon after the formation of the Earth's crust and the Earth
During Hadean time (4.6–4 Ga), the Solar System was forming, probably within a large cloud of gas and dust around the Sun, called an accretion disc from which Earth formed 8] The Hadean Eon is not formally recognized, but it essentially marks the era before we have adequate record of significant solid rocks.
The Cryptic era is an informal term for the earliest geologic evolution of the Earth and Moon.It is the oldest (informal) era of the Hadean eon, and it is commonly accepted to have begun close to about 4.533 billion years ago when the Earth and Moon formed, and lasted to about 4.15 billion years ago.
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Hades received the underworld, Zeus the sky, and Poseidon the sea, with the solid earth (long the province of Gaia) available to all three concurrently. In artistic depictions, Hades is typically portrayed holding a bident [ 5 ] and wearing his helm with Cerberus , the three-headed guard-dog of the underworld, standing at his side.