# Cosmic Timeline (WWCoC)

- <span style="text-decoration: underline;">4.6 Billion Years Ago/Ga (Gigaanum)</span>: The Sun and Solar System come into being
- <span style="text-decoration: underline;">4.54 Ga</span>: Earth Forms
- <span style="text-decoration: underline;">4.5 Ga:</span> Moon Forms
- <span style="text-decoration: underline;">4.4 Ga:</span> Oceans Form
- <span style="text-decoration: underline;">4.2 Ga</span>: Earliest possible emergence of life on earth
- <span style="text-decoration: underline;">3.5 Ga</span>: Life develops Photosynthesis
- <span style="text-decoration: underline;">717-660 </span><span style="text-decoration: underline;">Million Years Ago/Ma (Megaanum): </span>[Sturtian Glacial Episode](https://en.wikipedia.org/wiki/Sturtian_glaciation) (Snowball Earth)
- <span style="text-decoration: underline;">650-635 Ma:</span> [Marinoan Glacial Episode](https://en.wikipedia.org/wiki/Marinoan_glaciation) (Snowball Earth)
- <span style="text-decoration: underline;">575 Ma:</span> [Avalon Explosion](https://en.wikipedia.org/wiki/Avalon_explosion)
- <span style="text-decoration: underline;">525 Ma:</span> [Cambrian Explosion](https://en.wikipedia.org/wiki/Cambrian_explosion)
- <span style="text-decoration: underline;">444-445 Ma:</span> [Late Ordovician Mass Extinction Event](https://en.wikipedia.org/wiki/Late_Ordovician_mass_extinction)
- <span style="text-decoration: underline;">327 Ma:</span> [Late Devonian Mass Extinction Event](https://en.wikipedia.org/wiki/Late_Devonian_mass_extinction)
- <span style="text-decoration: underline;">252 Ma</span>: [Permian-Triassic Extinction Event](https://en.wikipedia.org/wiki/Permian%E2%80%93Triassic_extinction_event)
- <span style="text-decoration: underline;">201.3 Ma</span>: [Triassic-Jurassic Extinction Event](https://en.wikipedia.org/wiki/Triassic%E2%80%93Jurassic_extinction)
- <span style="text-decoration: underline;">66 Ma</span>: [Cretaceous-Paleogene Extinction Event](https://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_extinction_event)
- <span style="text-decoration: underline;">15-12 Ma:</span> Solar System Crosses Through the Radcliffe Wave