Re: tech: ASTRO: Sterilisation of planets

Chris (
Thu, 23 Sep 1999 13:40:22 -0600 (MDT)

> From: (Patrick Wilken)
> Thursday, September 23, 1999 Published at 10:04 GMT 11:04 UK

> Sterilised planets
> If a superflare occurred on our Sun, then the Earth would be subject to
> rapid heating, aurorae would ripple in every sky, the ionosphere would
> break up and the ozone layer would be destroyed.
> This would allow lethal radiation and charged particles from the Sun to
> reach the ground, destroying all life-forms except those protected in
> the deep oceans.

Which would mean that ecosystems based around hydrothermal vents in deep ocean trenches would possibly be the only ecosystems left completely intact. Indeed, they might be completely unperturbed.

If similar ecosystems exist around hydrothermal vents at the bottom of the putative liquid ocean of the Jovian moon, Europa, they would be unlikely to experience any difficulties.

> But their analysis has implications for the possibility of life in
> space.
> In recent years, many Jupiter-class planets have been discovered closely
> orbiting some of the nearest stars to our Solar System, raising the
> possibility that some of these newly-discovered planetary systems may
> harbour life.
> If superflares are common in these systems then they may sterilise the
> surfaces of accompanying planets, making life harder to develop.
> Alternatively, it may mean that life in these systems would evolve in
> protected regions such as deep caves or beneath the surface of an ocean.

Exactly. Hydrothermal vent-type life may be the norm for life in the galaxy. *We* might be the weird aliens who are exceptions to the general rules about where lifeforms live and how they feed themselves.

If this is the case, superflares may have less of an impact on the development of life elsewhere in the universe than it might at first appear.