Get caught up to speed on Season 1, a time known as The Hadean.The Hadean covers Earth's earliest days from 4.6 to 4 billion years ago, January 1 to Feb 14 on the Earth Calendar. This is a time of many firsts, including the formation of the Earth, Moon, oceans, islands, and perhaps life. Check out previous episodes for more details, like the women who mapped the Earth's inner core (6) and seafloor (11), the largest object to strike our planet (8), and our earliest ancestor (23).