According to a recent scientific paper, our planet narrowly escaped a catastrophic collapse of its magnetic field, the protective layer that shields Earth, some 565 million years ago.
Scientists say that had the magnetic field collapsed, life on Earth would have been nearly impossible.
They say that severe solar winds would have most likely stripped out planet of its atmosphere, causing harmful cosmic radiation to bombard the surface of the planet.
However, luckily, Earth’s core solidified ‘right in the nick of time’, causing its magnetic field to recharge just at the time when it was believed to have been at its weakest point.
The new paper suggests that Earth’s core is relatively young. The study also provides unprecedented insight into the formation of our planet’s core.
The scientific team was led by Richard Bono, a paleomagnetism researcher at the University of Rochester. Scientist traveled to what is now Canada’s eastern Quebec, where they analyzed and studied single crystals of plagioclase and clinopyroxene which are thought to have formed some 565 million years ago.
The results of their study allowed them to accurately reconstruct the timeline of our planet’s inner core ‘solidification.
The results have been published in Nature Geoscience.
“An enduring mystery about Earth has been the age of its solid inner core,” the experts wrote in the study.
Experts say they’ve come across unprecedentedly low geomagnetic field intensities, which suggest that there was an extremely high frequency of magnetic reversals around 565 million years ago, which indicates that the geodynamo was on the point of collapsing.
Image: A comparison of our planet around 565 million years ago, left, with a nascent solid inner core versus Earth today, on the right. Image credit: Michael Osadciw and John Tarduno / University of Rochester.
“We don’t have many real benchmarks for the thermal history of our planet,” explained Peter Olson, a geophysicist at Johns Hopkins University who was not involved in the new study.
“We know the interior was hotter than today because all planets lose heat. But we don’t know what the average temperature was a billion years ago, compared with today.”
Scientists further explain that estimates of when exactly Earth’s core solidified vary between 2.5 billion and as recent as 500 million years ago.
“The nucleation of the inner core may have occurred right in the nick of time to recharge the geodynamo and save Earth’s magnetic shield,” revealed experts.
“A young inner core is consistent with thermal history models of the Earth9–12 that predict a large transfer of heat from the core to the mantle due, indirectly, to upward revisions to the thermal conductivity of the core,” they concluded.
This study has many implications as it could help astronomers search for alien life, as it offers unprecedented insight into how exoplanets can sustain life.