Since we are all stuck at home, we want to invite you on a little journey. A journey to the past - about 2.5 billion years ago, at the end of the Archean eon that had started about 1.5 billion years before. This vast stretch of time included huge milestones for our planet, including the early days of the microcosmos. This is the story of the Great Oxidation Event, and how in the process of destroying the world as it existed, cyanobacteria like Spirulina created the Earth as we know it now.