If humans were to create artificial habitats in space, what natural planetary functions would these engineered constructs need to replicate?

Answer

Gravity, shielding, and resource cycling.

Artificial habitats designed to replace natural planets must replicate fundamental physics and chemistry requirements such as gravity, radiation shielding, and closed-loop resource recycling.

If humans were to create artificial habitats in space, what natural planetary functions would these engineered constructs need to replicate?
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