The Goldilocks zone gets its name from the fairy tale, “Goldilocks and the Three Bears”. Goldilocks is a fussy little girl whose porridge has to be just right — neither too hot nor too cold. It’s the same with life itself — or at least, the kind of water-based life we’re familiar with on Earth. 

For a planet has to be “just right”, or able to support life, it cannot be so  cold that water only exists as frozen ice, and it cannot be so hot that the water all boils away. Only planets  within a certain range of orbits dubbed the “Goldilocks zone” — or formally known as the “habitable zone” — are thought to be capable of supporting life.  

Habitable zone definition


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