Study says more planets could support alien life

Underground water could greatly increase the chances of planets harbouring extraterrestrial life, scientists believe.

Taking into account sub-surface habitats broadens the range of places life-sustaining planets can occupy, a study has found.

It means there could be around seven times more life-bearing planets among the stars than is currently believed.

Potentially habitable rocky planets are said to lie in the “Goldilocks zone” – the narrow orbital path that is not too close to their star and not too far away, but “just right” to support surface liquid water.

Several such worlds have already been discovered. But including the possibility of life below the ground means the Goldilocks zone can be wider, thereby increasing the number of planets on which organisms could dwell, it is claimed.

Lead researcher Sean McMahon, from the University of Aberdeen’s School of Geosciences, said: “We have developed a new model to show how Goldilocks zones can be calculated for underground water and hence life.

“Many more habitable planets exist if you are prepared to take into account sub-surface life.”

The research was presented at the British Science Festival, taking place at the University of Aberdeen.