When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. History of Earth - Wikipedia

    en.wikipedia.org/wiki/History_of_Earth

    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

  3. Age of Earth - Wikipedia

    en.wikipedia.org/wiki/Age_of_Earth

    The oldest such minerals analyzed to date—small crystals of zircon from the Jack Hills of Western Australia—are at least 4.404 billion years old. [ 6 ] [ 9 ] [ 10 ] Calcium–aluminium-rich inclusions —the oldest known solid constituents within meteorites that are formed within the Solar System —are 4.567 billion years old, [ 11 ] [ 12 ...

  4. Geologic Calendar - Wikipedia

    en.wikipedia.org/wiki/Geologic_Calendar

    A variation of this analogy instead compresses Earth's 4.6 billion year-old history into a single day: While the Earth still forms at midnight, and the present day is also represented by midnight, the first life on Earth would appear at 4:00 am, dinosaurs would appear at 10:00 pm, the first flowers 10:30 pm, the first primates 11:30 pm, and ...

  5. Geologic time scale - Wikipedia

    en.wikipedia.org/wiki/Geologic_time_scale

    Chaotian Era/Erathem (4567–4404 Ma) – the name alluding both to the mythological Chaos and the chaotic phase of planet formation. [64] [77] [78] Jack Hillsian or Zirconian Era/Erathem (4404–4030 Ma) – both names allude to the Jack Hills Greenstone Belt which provided the oldest mineral grains on Earth, zircons. [64] [77]

  6. Geological history of Earth - Wikipedia

    en.wikipedia.org/wiki/Geological_history_of_Earth

    The Precambrian includes approximately 90% of geologic time. It extends from 4.6 billion years ago to the beginning of the Cambrian Period (about 539 Ma).It includes the first three of the four eons of Earth's prehistory (the Hadean, Archean and Proterozoic) and precedes the Phanerozoic eon.

  7. Earth Day 2024: Why was Earth Day created, and how to ... - AOL

    www.aol.com/earth-day-2024-why-earth-161633692.html

    Earth Day 2024 is almost here. Here's everything to know about the day, its history and how it's celebrated. ... The first Earth Day was held April 22, 1970. The date was chosen because it fell ...

  8. Hadean - Wikipedia

    en.wikipedia.org/wiki/Hadean

    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 ...

  9. Earliest known life forms - Wikipedia

    en.wikipedia.org/wiki/Earliest_known_life_forms

    The age of Earth is about 4.54 billion years; [7] [33] [34] the earliest undisputed evidence of life on Earth dates from at least 3.5 billion years ago according to the stromatolite record. [35] Some computer models suggest life began as early as 4.5 billion years ago. [36] [37] The oldest evidence of life is indirect in the form of isotopic ...