Hmm, okay, so picture this—way back about 4.5 billion years ago, the Earth was basically just a hot ball of rock and metal forming out of dust and gas in space, kind of like a cosmic construction site. At first it was way too hot for life, and the atmosphere was full of stuff like methane, ammonia, and hydrogen—but not the oxygen we breathe today.  

Want me to walk you through how it cooled down and got oceans? That part’s pretty wild.