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11 maj 2023 · Our Sun formed about 4.57 billion years ago from a cloud of collapsing dust and gas, in an unremarkable corner of the Milky Way galaxy. The material left over the Sun’s formation coalesced into everything else in our Solar System, including Earth, which was born around 4.55 billion years ago.
Oxygen began building up in the prebiotic atmosphere at approximately 1.85 Ga during the Neoarchean-Paleoproterozoic boundary. At current rates of primary production, today's concentration of oxygen could be produced by photosynthetic organisms in 2,000 years. [4]
At some point early in the game, perhaps within hundreds of millions of years of Earth's formation, a mechanism for pulling energy provided by sunlight from certain chemicals was chanced upon. Though it was technically photosynthesis, it wasn't the kind that left an excess of oxygen.
12 gru 2022 · On modern Earth, the dominant tectonic activity is called plate tectonics, where oceanic crust — the outermost layer of Earth under the oceans — sinks into Earth’s mantle (the area between...
19 paź 2023 · The hydrogen protons began fusing, forming helium and releasing massive amounts of energy. This led to the formation of the star that is the center point of our solar system—the sun—roughly 4.6 billion years ago. Planet Formation. The formation of the sun consumed more than 99 percent of the matter in the nebula.
19 sie 2009 · So how did Earth end up with an atmosphere made up of roughly 21 percent of the stuff? The answer is tiny organisms known as cyanobacteria, or blue-green algae.
