Photosynthesising bacteria amongst the Archaea ( Archean Eon)Įarliest atmospheric oxygen, present at low levels ( Archean Eon) Ignition of hydrogen stars, bathing the Universe in first light of cosmic dawn → earliest galaxies of stars forming 400 million years after the Big Bang helium in stars fusing into carbon, leading to stellar nucleosynthesis of all elementsĮarliest water: an interstellar vapour, and repository for oxygenįormation of the Milky Way galaxy, a warped disc of 100 billion stars, now one of 2 trillion galaxies in the observable Universeįormation of the Sun and Solar System within the Milky Way, orbiting a supermassive black hole at its Galactic Centre every 240 million yearsįormation of the Moon from a giant impact with proto-Earthįormation of planet Earth with 510 million km² of surface area, orbiting the Sun on a yearly cycle, rotating eastward on a daily cycle around a tilted axis that perpetuates opposing polar seasonsįormation of Earth’s oceans and moist atmosphere, protected from solar wind and cosmic rays by Earth’s magnetosphere generated by its iron coreĮarliest subduction of Earth’s crust → continental plate tectonics by 3 billion years ago, unique to Earth in the Solar SystemĮarliest life on Earth: single-celled prokaryotic Archaea ( Hadean Eon, 3.8-4.2 billion years ago) Discs fill with colour as time passes towards the present (further explanation below ⇓)īig Bang singularity, creation of all particles of matter and counterpart antimatter, and the laws of physics governing their interactions expansion and cooling of space → formation of the observable Universe, its galaxies, solar systems, stars, planets, moons, asteroids and comets

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