Psience Quest

Quote:It would be bad enough if just Earth’s magnetic field was weakened, but ice core data showed an unfortunate coincidence: during the Adams Event, the sun was also in a period of lowered activity. While that might have meant fewer solar flares, it also means that the protective shield the sun creates against cosmic rays—called the heliosphere—was also weakened.

With both its magnetic field and heliosphere diminished, Earth was doubly at risk from cosmic radiation, according to the study.

That would be really bad news today, given space weather’s effect on satellites and the power grid. But what would it mean for life 42,000 years ago?

“It must have seemed like the end of days,” says University of New South Wales geoscientist Chris S.M. Turney, a co-author of the new study, to Alanna Mitchell at the New York Times.

The effects may have included a thinning ozone layer, the aurora borealis approaching close to the equator, an increase in ultraviolet radiation reaching the surface, raging electrical storms, and Arctic air reaching across continents, the authors write on the Conversation.

They link the environmental effects to the extinction of large animals in Australia, the eventual demise of Neanderthals and humans’ use of red ocher pigment for cave art and sunscreen.