Saturday, 19 April 2014
New Exoplanet Kepler-186f Is Life Friendly?
Kepler-186f, a star orbiting a red dwarf star some 500 light years from us is the latest exoplanet that might just about have liquid water. And, in a Darwinian scenario, water almost always means that there might be life.
The planet is comfortably within the star’s habitable zone.
What is often overlooked is that Venus and Mars also orbit the Sun in the habitable zone, so any declaration of the certainty of alien life might be a bit premature, especially as red dwarfs – unlike our sun – are known to be somewhat unstable.
Writing in Answers magazine, astronomer Danny Faulkner states:
“Red and orange stars produce dangerous magnetic activity. Since these stars are cooler than the sun, habitable planets must orbit more closely – and face greater harm. Another potential problem is insufficient radiation to support photosynthesis.”
New Scientist likewise acknowledges some of the difficulties:
“Red dwarf stars are highly active, producing frequent flares and strong winds of radiation. And as Kepler-186f is slightly larger than Earth, if it has a similar internal structure, it would support a stronger magnetic field. That would spark interactions between any potential atmosphere and stellar radiation that could create frequent and spectacular auroras visible from large regions of the planet.”
However, spectacular auroras are not what life would first and foremost need. Many astronomers know that in contrast to Earth, exoplanets tend to be more or less weird, and some will admit that contrary to evolutionary expectations, alien life might not even exist.
Among the trillions of stars, there’s no place like home.
Faulkner, Danny. 2014. Not just another star. Answers 9 (1): 66–67.
Grossman, Lisa. 2014, Smallest life-friendly exoplanet may be lit by auroras. New Scientist (17 April).