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One of the hypothesis for the Late Ordovician mass extinction event, which killed off about 85% of all marine species at the time, is an unfortunate burst of ga

One of the hypothesis for the Late Ordovician mass extinction event, which killed off about 85% of all marine species at the time, is an unfortunate burst of gamma rays, about 10 seconds long, from regions of space at least thousands of light years away. [1] One star goes boom and blanks out life on a planet thousands of light years away. The brutality of our universe cannot be overstated. It's one of the many reasons life being multiplanetary is so important. There's no reason this, a giant asteroid, supervolcano, or any other of the million possible ways the universe can think up to kill us all off won't happen. In fact it will happen, sooner or later - and we're overdue. Of course the odds of it happening tomorrow are near zero, but that will be just as true the day before it happens. And the number of things that can wipe out two wildly different planets simultaneously is a small subset of all things that can wipe out 1. And the same is true as we expand on outward to new star systems, eventually even new galaxies, and perhaps further yet beyond that. [1] - https://en.wikipedia.org/wiki/Late_Ordovician_mass_extinction#Gamma-ray_burst https://en.wikipedia.org/wiki/Late_Ordovician_mass_extinctio...

SketchySeaBeast 3y ago
Given that ~14 feet of water attenuates gamma rays by a factor of a billion[1], and it had to reach earth from 6,000 light years away, that's an absolutely gobsmacking amount of energy. With the factors of power involved I don't think being on another planet would have helped that much. Even if we were a few light years away the hypothesized burst travelled thousands of light years to get here and we don't know what direction the next killing bolt will come from (I suppose we could go further away from the galactic core to reduce the highest odds, but still). And it still had enough power to cause decimation a billion times over if we weren't underwater. [1] https://stemrad.com/cbrn-gamma-radiation/ https://stemrad.com/cbrn-gamma-radiation/
- throwaway290 3y ago
  It really shows how it is a massive waste to colonize Mars compared to stuff like preserving Earth and maybe researching ways of shielding from all sorts of radiation (that would also make interplanetary space travel possible without dying quickly after arrival, by the way, and living on planets without magnetosphere).
  - njarboe 3y ago
    For the preservation of life in this single case it would be a waste but there as so many other scenarios where it would work. Plus there are so many other reasons to have a human civilization and terrestrial life spread to Mars. Humanity can do more than one thing at a time.
    - somenameforme 3y ago
      Even in this event Mars would have been a safe haven. Unlike Earth, the atmosphere on Mars is completely toxic with the planet exposed to dangerously high levels of radiation. Not exactly what one would call benefits, but in this case they would be, because human settlement on Mars would already entail the sort of lifestyle and technology that would render this sort of catastrophe relatively harmless.
      - throwaway290 3y ago
        Nonsensical argument, this shielding has to exist on Earth first (we are rolling the dice otherwise), deciding to colonize Mars adds nothing except a colossal waste of time and effort on other things.
        somenameforme 3y ago
        Shielding isn't some distant future technology. Many simple compounds work as great shields, including water. That's been proposed as one of the ways to deal with extreme space weather events when traveling to Mars - using the water storage as an emergency shield. But of course you can't just put some giant shield up over the entire Earth for many reasons that I think should be pretty clear? Unfortunately, Earth will literally never be safe from extinction. Nor will any planet. The first thing that should happen once we set foot on Mars is planning for the settlement of the next planet, or moon, to follow. That doesn't mean we should neglect any planet, most obviously including Earth, but the benefit of having 8 billion people is we're more than capable of doing more than one thing at a time.
- adhesive_wombat 3y ago
  It (is hypothesised that) wasn't that gamma radiation that directly killed the plankton, it damaged the ozone layer so that normally-blocked solar UV killed the plankton.

SketchySeaBeast 3y ago

Given that ~14 feet of water attenuates gamma rays by a factor of a billion[1], and it had to reach earth from 6,000 light years away, that's an absolutely gobsmacking amount of energy. With the factors of power involved I don't think being on another planet would have helped that much. Even if we were a few light years away the hypothesized burst travelled thousands of light years to get here and we don't know what direction the next killing bolt will come from (I suppose we could go further away from the galactic core to reduce the highest odds, but still). And it still had enough power to cause decimation a billion times over if we weren't underwater. [1] https://stemrad.com/cbrn-gamma-radiation/ https://stemrad.com/cbrn-gamma-radiation/

throwaway290 3y ago
It really shows how it is a massive waste to colonize Mars compared to stuff like preserving Earth and maybe researching ways of shielding from all sorts of radiation (that would also make interplanetary space travel possible without dying quickly after arrival, by the way, and living on planets without magnetosphere).
- njarboe 3y ago
  For the preservation of life in this single case it would be a waste but there as so many other scenarios where it would work. Plus there are so many other reasons to have a human civilization and terrestrial life spread to Mars. Humanity can do more than one thing at a time.
  - somenameforme 3y ago
    Even in this event Mars would have been a safe haven. Unlike Earth, the atmosphere on Mars is completely toxic with the planet exposed to dangerously high levels of radiation. Not exactly what one would call benefits, but in this case they would be, because human settlement on Mars would already entail the sort of lifestyle and technology that would render this sort of catastrophe relatively harmless.
    - throwaway290 3y ago
      Nonsensical argument, this shielding has to exist on Earth first (we are rolling the dice otherwise), deciding to colonize Mars adds nothing except a colossal waste of time and effort on other things.
      - somenameforme 3y ago
        Shielding isn't some distant future technology. Many simple compounds work as great shields, including water. That's been proposed as one of the ways to deal with extreme space weather events when traveling to Mars - using the water storage as an emergency shield. But of course you can't just put some giant shield up over the entire Earth for many reasons that I think should be pretty clear? Unfortunately, Earth will literally never be safe from extinction. Nor will any planet. The first thing that should happen once we set foot on Mars is planning for the settlement of the next planet, or moon, to follow. That doesn't mean we should neglect any planet, most obviously including Earth, but the benefit of having 8 billion people is we're more than capable of doing more than one thing at a time.
adhesive_wombat 3y ago
It (is hypothesised that) wasn't that gamma radiation that directly killed the plankton, it damaged the ozone layer so that normally-blocked solar UV killed the plankton.