The Sun Factor

The obsession with sunscreen and sun-protecting gadgets is not new: Ancient Homo sapiens had already learned to fear the harsh rays of the sun tens of thousands of years ago. 

In fact, our human ancestors used sunscreen, tailored clothing, and cave shelters to hide from harmful solar radiation during the shifting of the magnetic North Pole over Europe about 41,000 years ago, according to a new study. 

At the same time, researchers say they believe Neanderthals didn’t protect themselves, probably because they couldn’t, and disappeared around that time. 

As Earth’s outer molten core moves, it creates electric currents, which in turn generate a magnetic field that acts like a shield and protects Earth from dangerous cosmic radiation. Currently, this field is strongest near the two poles, the North and South Poles, which is where auroras manifest, New Atlas wrote.  

However, the poles are not constant and can be located elsewhere in a phenomenon known as geomagnetic excursion, which has happened over 180 times in Earth’s history. The latest instance of this event, about 41,000 years ago, is known as the Laschamp excursion. 

Although the magnetic reversal didn’t fully occur that time, with a 3D reconstruction of Earth’s geospace system, researchers concluded that the Earth’s magnetic field weakened to 10 percent of its usual strength. This caused auroras to be visible across much of Earth and allowed more harmful ultraviolet (UV) and cosmic radiation to reach the planet.  

“In the study, we combined all of the regions where the magnetic field would not have been connected, allowing cosmic radiation, or any kind of energetic particles from the sun, to seep all the way in to the ground,” said lead author Agnit Mukhopadhyay in a statement. 

The 3D reconstruction indicated that the Laschamp excursion happened in a brief window of time when H. sapiens and Neanderthals co-existed. The consequences of the excursion posed serious health risks to those populations, from eye problems to birth defects. As a result, researchers say this study could offer a new theory to explain why around 41,000 years ago, H. sapiens thrived while Neanderthals disappeared. 

“Having protection against solar radiation would also have conferred a significant advantage to anyone who possessed it,” said study author Raven Garvey in the statement. 

Archaeological data show an increased use of caves and tailored clothing, which trapped warmth while blocking dangerous rays, and allowed H. sapiens to leave their shelters to find food. 

Researchers say that the ancient humans also used red and yellow ochre pigments more frequently in this period. Ochre, made up of iron oxide, clay, and silica, is not only used as paint for art, but, when ground and applied to the skin, has the property of a mineral-rich sunscreen.