Asteroids Had Magnetic Fields That Could Have Protected Hitchhiking Lifeforms – Popular Mechanics
Our planet’s trusty magnetic field—an invisible barrier created by the churning of molten-hot matter in Earth’s core—protects us from the lethal space radiation that engulfs most of the known universe. Without this field, Earth today would look as barren as Mars. Scientists have a hard time imagining how life anywhere could exist without one.
According to a new study out today, magnetic fields like Earth’s may have been far more common in our early universe than scientists ever suspected. As a team of planetary scientists led by James Bryson of the University of Cambridge reports in the journalNature, space rubble such as asteroids and meteoroids once created their own powerful magnetic fields that lasted for millions to tens of millions of years. This new discovery not only radically alters our understanding of asteroid evolution, but also bolsters the possibility that life—or the delicate chemical precursors to life—could survive by hitchhiking on space rubble.
“The fact that you can get this very efficient, very long-lived magnetic activity on asteroids is really going to change the perspective on how we think these things evolved,” Bryson says. “And from an even wider perspective, I think it’s also becoming incredibly apparent that asteroids in many ways are just small, sped-up versions of our own planet.”