Key Events

• The Earth forms through accretion (rubble from the Solar System clumping together).
• Initially, its surface is molten.
• As Earth cools, minerals separate based on density to create the crust, mantle and core.
• The Moon forms, most likely through a collision betweenEarth and a body the size of Mars, 4,500 million years ago.
• Earth becomes covered in water.

Facts, Debates & Trivia

• The eon is named after Hades, god of the Underworld, because of the hellish conditions.
• We don’t know how or when Earth acquires its water. It might come from impacts by icy comets or be ‘outgassed’ from water held internally.
• Just like Earth, Mars also acquires water during this time.

Conditions

• The newborn Earth is a hostile environment!
• Temperatures are scorching hot from the accretion process and heating from radioactive elements.
• There are high radiation levels.
• Earth has  frequent collisions with other bodies in the Solar System.

Timeline

4,600-4,000 million years ago (600 million years)

Where have you reached on the trail?