The age of Earth is approximately one-third of the age of the universe. An immense amount of biological and geological change has occurred in that time span. Earth formed around 4.54 billion years ago by accretion from the solar nebula.Volcanic outgassing probably created the primordial atmosphere, but it contained almost no oxygen and would have been toxic to humans and most modern life.he age of Earth is approximately one-third of the age of the universe. An immense amount of biological and geological change has occurred in that time span. Earth formed around 4.54 billion years ago by accretion from the solar nebula.