Stage 8

Earth

The living chapter — oceans, air, life

Oceans, breathable air, a biosphere. The only world we know that completed the sequence into a living planet.

What the cameras and papers show

About 71% of the surface is ocean. The air is one bar of nitrogen and oxygen. Plate tectonics recycles the crust: almost all of the present seafloor is younger than 200 million years.

Earth’s water is at least 3.8 billion years old. Life is at least that old in the rock record. Compatibility with a long-lived ocean is not a trophy for the cycle.

Earth’s Moon is not used on this site. It belongs to a later paper.

How this site reads it

Earth is the living stage. Venus and Mercury are read as an earlier turn, already spent.

Life is Earth’s. No other world on this list has a detected biosphere.

What would kill this stage

If everything about Earth is explained as a first-generation inner planet, with nothing left from an earlier stage, the cycle reading of Earth comes off the table.