Resilience of life to Astrophysical Events

[jim mcnamara]

https://www.nature.com/articles/s41598-017-05796-x

Abstract:

Much attention has been given in the literature to the effects of astrophysical events on human and land-based life. However, little has been discussed on the resilience of life itself. Here we instead explore the statistics of events that completely sterilise an Earth-like planet with planet radii in the range 0.5–1.5R⊕ and temperatures of ∼300 K, eradicating all forms of life. We consider the relative likelihood of complete global sterilisation events from three astrophysical sources – supernovae, gamma-ray bursts, large asteroid impacts, and passing-by stars. To assess such probabilities we consider what cataclysmic event could lead to the annihilation of not just human life, but also extremophiles, through the boiling of all water in Earth’s oceans. Surprisingly we find that although human life is somewhat fragile to nearby events, the resilience of Ecdysozoa such as Milnesium tardigradum renders global sterilisation an unlikely event.

Milnesium is a tardigrade. They can resist severe dessication, extreme heat, and extreme cold.

 

[mfb]

We have microbes living under kilometers of rock. Heating the whole surface of Earth for a long time is the only realistic way to kill them.

 

[jim mcnamara]

That is a distinct shortcoming of the paper. But they are Astrophysicists. I take it they used tardigrades as the bellwether species.

 

[mfb]

Well, everything that boils the oceans will also heat up the mantle. It just takes a bit longer, and I don't know how much it has to heat up to kill all the microbes there.

 

[Ygggdrasil]

Life is capable of surviving in some fairly extreme environments. Microbial life may be more resilient than tardigrades. See the table below from this review on microbial extremophiles:
https://academic.oup.com/femsre/article-lookup/doi/10.1093/femsre/fuw015

 

[Laroxe]

Apparently bacteria can survive in space, some have been deliberately attached to the outside of the space station in transparent containers but its suggested that others have been found in exposed areas. Now that is a hostile environment, I think its cause some interest in the potential to seed Mars.
https://www.nationalgeographic.com/...-international-space-station-germy-humans-spd