Goldilock's phenomenon

In astronomy, the Goldilocks phenomenon refers to the necessity that planetary conditions such as size or temperature be “just right” in order to sustain life.
The term derives from Goldilocks, the story of a girl who prefers porridge which is “not too hot and not too cold”.
Our solar system’s habitable zone, which is likewise neither too hot nor too cold for life to exist, is where the earth is found.
Astronomer Lames Lovelock is credited with coining the term.