April 22 is Earth Day, a day to celebrate our planet and pledge to preserve it. Though Earth Day has only been widely observed since 1970, many cultures have set aside days dedicated to the Earth and its natural elements for thousands of years. The ancient Greeks, for example, celebrated Gaia, or “Mother Earth.” The USA Greek Reporter explains that Gaia was known as one of the earliest deities. She was an important figure in Greek mythology, having emerged from Chaos to become the first Greek goddess. She was considered a literal and figurative Mother Earth, creating the earth and the universe, and giving birth to hundreds of gods and goddesses.