The term ‘Goldilocks planet’ refers to any planet in the Universe that lies within the habitable zone of a star. The habitable zone itself is an area of space around the star where temperatures are sufficient to permit the existence of liquid water on the planet’s surface. The idea is that if there is liquid water, life can exist.
The Copernican Principle
The notion is based on the Copernican Principle that the Earth is not unique in the Universe and that other Earth-like planets exist. Goldilocks comes from the fairy tale ‘Goldilocks and the Three Bears’. A little girl explores the bears’ cottage and chooses between three bowls of porridge, chairs and beds to find which item is “just right”.
The Goldilocks planet in the habitable zone should be similar to the Earth with a solid surface. Gaseous planets such as Saturn or Jupiter are not thought to be capable of sustaining life. Even if an Earth-like planet orbits within the habitable zone of a star, it may still not hold life. [Read more…]