Quirks and Quarks

Scientists figure out how to wipe out all life on Earth

It's good news for alien hunters that Earth's hardiest creature, the tardigrade, can survive astrophysical doomsday scenarios.
What kind of global catastrophe could wipe out all life on our planet?

Our world has been through a lot - asteroids, solar flares, ice ages, events which have caused major extinctions, like the asteroid that wiped out the dinosaurs.

But even after spectacular catastrophes, life has always managed to bounce back, which made one group of scientists wonder - what would it take to kill everything?

Dr. Rafael Alves Batista, a physicist and postdoctoral researcher at the University of Oxford, and his colleagues did the math and some modelling - to see how big a disaster they would need to obliterate life completely. They didn't look at human life though. When it comes to major doomsday scenarios, like massive asteroids, supernovae, and gamma-ray bursts, we're just a wee bit too fragile. Instead they focussed a much tougher life form: a tiny animal called a tardigrade, which is ridiculously hard to kill.

Animation of a tardigrade 

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