The Earth experienced a period of extreme cold known as the Cryogenian period, which spanned approximately 100 million years, from 720 million to 635 million years ago. During this time, the Earth's surface was almost entirely covered in ice, reaching as far as the equator. Scientists believe that this global glaciation was triggered by a combination of factors, including changes in the Earth's orbit, variations in solar radiation, and the rise of oxygen levels in the atmosphere. The Cryogenian period had a profound impact on the Earth's geology and biology, leading to the formation of unique rock formations and the evolution of life in extreme environments.
