Life could exist 'much further from the sun' than previously thought
Planets and moons could support life at distances from their star far
greater than previously thought, according to research carried out in
Scotland.
Scientists said the traditional "Goldilocks" model of planets which
could sustain life - ones that are not too hot and not too cold - does
not take into account the fact that liquid water can exist deep below
the surface.
The team from the University of Aberdeen, conducted computer
modelling which suggested the habitable zone for an Earth-sized planet
could be as much as 14 times wider than previously thought.
They concluded that it must include "many more planets", and said it
could even mean ours is actually unusual for having its life
predominantly on the surface.
Lead author and PhD student Sean McMahon explained the team's
findings: "The deepest known life on Earth is 5.3km below the surface,
but there may well be life even 10km deep in places on Earth that
haven't yet been drilled.
"Using our computer model we discovered that the habitable zone for
an Earth-like planet orbiting a sun-like star is about three times
bigger if we include the top five kilometres below the planet surface.
"The model shows that liquid water, and as such life, could survive
5km below the Earth's surface even if the Earth was three times further
away from the sun than it is just now.
"If we go deeper, and consider the top 10km below the Earth's
surface, then the habitable zone for an Earth-like planet is 14 times
wider." He added: "The results suggest life may occur much more commonly
deep within planets and moons than on their surfaces. This means it
might be worth looking for signs of life outside conventional habitable
zones. "I hope people will study the ways in which life below the
surface might reveal itself.
"Earth might even be unusual in having life on the surface."
- The Independent |