Hadean Eon (4.6 to 4 billion years ago): This eon begins with the formation of the Earth and spans until about 4 billion years ago. It is characterized by intense heat and constant bombardment by asteroids and comets.

Archean Eon (4 to 2.5 billion years ago): During this eon, the Earth’s crust solidified, and the first signs of life appeared around 3.8 billion years ago. Simple single-celled organisms emerged, marking the early stages of life on Earth.

Proterozoic Eon (2.5 billion to 541 million years ago): Multicellular life forms evolved during this eon, and the Earth’s atmosphere began to accumulate oxygen due to the photosynthetic activities of early organisms.

Phanerozoic Eon (541 million years ago to present): This is the eon we are currently in. It is characterized by the proliferation of complex life forms, including plants, animals, and fungi. It is further divided into three eras: Paleozoic, Mesozoic, and Cenozoic.

The total duration from the beginning of the Hadean Eon to the present day is approximately 4.6 billion years.