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  2. Geological history of oxygen - Wikipedia

    en.wikipedia.org/wiki/Geological_history_of_oxygen

    Photosynthetic prokaryotic organisms that produced O 2 as a byproduct lived long before the first build-up of free oxygen in the atmosphere, [5] perhaps as early as 3.5 billion years ago. The oxygen cyanobacteria produced would have been rapidly removed from the oceans by weathering of reducing minerals, [citation needed] most notably ferrous ...

  3. Great Oxidation Event - Wikipedia

    en.wikipedia.org/wiki/Great_Oxidation_Event

    Oxygen, O 2, meanwhile, was present in the atmosphere at just 0.001% of its present atmospheric level. [12] [13] The Sun shone at about 70% of its current brightness 4 billion years ago, but there is strong evidence that liquid water existed on Earth at the time. A warm Earth, in spite of a faint Sun, is known as the faint young Sun paradox. [14]

  4. Proterozoic - Wikipedia

    en.wikipedia.org/wiki/Proterozoic

    One of the most important events of the Proterozoic was the accumulation of oxygen in the Earth's atmosphere. Though oxygen is believed to have been released by photosynthesis as far back as the Archean Eon, it could not build up to any significant degree until mineral sinks of unoxidized sulfur and iron had been exhausted. Until roughly 2.3 ...

  5. Neoproterozoic oxygenation event - Wikipedia

    en.wikipedia.org/wiki/Neoproterozoic_oxygenation...

    The Neoproterozoic Oxygenation Event (NOE), also called the Second Great Oxidation Event, was a geologic time interval between around 850 and 540 million years ago during the Neoproterozoic era, which saw a very significant increase in oxygen levels in Earth's atmosphere and oceans. [1]

  6. Cambrian explosion - Wikipedia

    en.wikipedia.org/wiki/Cambrian_explosion

    Oxygen levels in the atmosphere increased substantially afterward. [132] As a general trend, the concentration of oxygen in the atmosphere has risen gradually over about the last 2.5 billion years. [23] Oxygen levels seem to have a positive correlation with diversity in eukaryotes well before the Cambrian period. [133]

  7. Oxygen - Wikipedia

    en.wikipedia.org/wiki/Oxygen

    Dioxygen gas currently constitutes 20.95% molar fraction of the Earth's atmosphere, though this has changed considerably over long periods of time in Earth's history. Oxygen makes up almost half of the Earth's crust in the form of various oxides such as water, carbon dioxide, iron oxides and silicates. [6]

  8. The time when a day on Earth was just 19 hours long - AOL

    www.aol.com/lifestyle/day-earth-used-just-19...

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  9. Atmosphere of Earth - Wikipedia

    en.wikipedia.org/wiki/Atmosphere_of_Earth

    Earth is approximately 290 K (17 °C; 62 °F), so its radiation peaks near 10,000 nm, and is much too long to be visible to humans. Because of its temperature, the atmosphere emits infrared radiation. For example, on clear nights Earth's surface cools down faster than on cloudy nights.