The reason for the high level of Oxygen in the atmosphere today is due to the billions of years worth of photosynthetic prokaryotes releasing it as a waste product. Of course, in the higher levels of the atmosphere, oxygen becomes ozone, filtering the worst of the Sun's UV radiation to levels tolerable to humans.

I was thinking of a world that humans have settled upon. In many respects, the planet is similar to Earth, but perhaps younger, and crucially, no indigenous life, much less photosynthetic lifeforms

My question is this -

In a world devoid of oxygen-producing lifeforms, is there any alternative to the creation of an ozone layer, or an alternative substance with the same effect?

Additionally, are there any methods that can be used to create an artificial ozone layer, and what is the timescale involved?

Any answers would be greatly appreciated.

  • $\begingroup$ I've added a tag, hope it helps attract people with the right skills. Feel free to revert if you feel it's appropriate. $\endgroup$ – Tantalus' touch. Dec 31 '19 at 2:49
  • $\begingroup$ I'm not an expert far from being one but I think comet is the only abiotic option. $\endgroup$ – user6760 Dec 31 '19 at 2:59
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    $\begingroup$ Q; why would you need an alternative? No O2 producers means no O2 consumers (no plants, no animals and especially as we know them). Why bother with an O3 layer at all? Presumably, whatever life exists on this planet shall simply have evolved without an O3 layer. $\endgroup$ – elemtilas Dec 31 '19 at 3:49
  • $\begingroup$ How can human settle on a planet devoid of oxygen? $\endgroup$ – L.Dutch - Reinstate Monica Dec 31 '19 at 4:58
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    $\begingroup$ This looks similar. Not sure I agree with answer, but same question. What gas can replace ozone as a UV filter in a planet's atmosphere? $\endgroup$ – Willk Dec 31 '19 at 5:58