|Our early Earth was a molten world|
And arise they did. On the planet's surface, volcanoes spewed lava and volatile gasses into what would become our earliest atmosphere.
Again, in composition, it looked very different from the one we know today. Nitrogen, carbon dioxide, ammonia, methane and small amounts of water vapour made up the gassy soup surrounding our world.
But that first water would change everything. As the water vapour condensed, it came back to the surface bit by bit. Over a very long period of time, those waters pooled and gathered and became our first oceans. It was in this early ocean some 2.7 billion years ago that cyanobacteria, or blue-green algae, wonderous photosynthetic microbes, would take up that weakened sunlight and water vapour to process the carbon dioxide from the atmosphere, producing other chemical compounds and oxygen as a by-product.