42,000 years ago
Did an Ancient Magnetic Field Reversal Cause Chaos for Life on Earth 42,000 Years Ago? The study links new, detailed data about Earth’s atmosphere to a series of unfortunate events that occurred around the same time The study begins with fossilized Kauri trees (pictured) that died over 41,000 years ago. ( Nelson Parker via University of New South Wales ) By Theresa Machemer SMITHSONIANMAG.COM FEBRUARY 23, 2021 Humans today take Earth’s magnetic North Pole for granted. But over the course of the planet’s history, the direction of its magnetic field has shifted. A new study suggests that the last time the field flipped around and flopped back again, the effects on Earth’s surface were cataclysmic, Carolyn Gramling reports for Science News . The study, published on February 19 in the journal Science , makes use of massive, fossilized Kauri trees from New Zealand to create a timeline of how cosmic rays impacted Earth’s atmosphere during their lifetimes, which o...