- It refers to a habitable zone in the planetary system where the temperature is neither too high nor too low.
- Such conditions could allow for the presence on the planet’s surface of liquid water – a key ingredient for life.
- If a planet is too close to the star it orbits, any water on the surface quickly boils off, forming a steam atmosphere.
- If the planet is too far from the star, any water on the surface freezes.
- The habitable zone (or “Goldilocks zone”) is the range of orbital distances from a star at which liquid water can exist on the surface of a planet.
- This range of distances changes depending on the size and temperature of the star.
- Earth is in the habitable zone of the sun – one of the reasons our planet has liquid water like oceans and lakes.