There are billions of exoplanets in our own galaxy alone and thanks to the Keplar telescope we are discovering more and more all the time. Astronomers are united in their belief that, although many are gas giants, several planets do exist within the Goldilocks zone, suggesting they could be life-harbouring planets just like Earth.
However a new study conducted by scientists at the Institute of Mineralogy, in Paris, France has found these so called earth-like planets may simply be dead zones that harbour no life at all because the magnetic field that protects planets from space radiation, may be absent. Any planet that qualifies as life friendly needs have a temperature not too hot (close to its parent star) and not too cold (far from its parent star).
Just like Goldilocks whose illicitly-consumed porridge was too hot, too cold and finally just right in temperature to eat, exoplanets in this temperate zone have long been believed to hold the greatest chance of alien life existing extra-terrestrially to our own planet earth. But without the magnetic field, harmful and life-threatening radiation would destroy any chance of life existing because of the particles that would bombard that planet.
Take Mars for example, here is a planet that has lost its magnetic field. A planet would need a metallic molten core to create a magnetic field. We have analysed Mars and determined its magnetic field was switched off around half-a-billion years ago.
More than a thousand exoplanets have been discovered so far. The vast majority are gas giants that are too close to their parent suns to support life. The earth-like exoplanets may have molten cores that are too hot to maintain life. This means that although some of these exoplanets do lie within the Goldilocks zone, it does not mean the temperature on the surface makes it necessarily life-harbouring at all.