A study released earlier this month by NASA scientists has revealed a surprising uptick in solar activity, challenging previous expectations that the sun was entering a prolonged period of historical inactivity.

"All signs were pointing to the sun going into a prolonged phase of low activity," said lead author Jamie Jasinski, a space plasma physicist at NASA's Jet Propulsion Laboratory in Southern California. "So it was a surprise to see that trend reversed. The sun is slowly waking up."

The study was published in early September in The Astrophysical Journal Letters.

According to NASA, solar activity had been steadily declining from the 1980s until 2008, "when solar activity was the weakest on record." So scientists at that point predicted that the sun might be approaching a period of historically low activity.

However, since 2008, researchers have observed a gradual increase in solar behavior, a reversal which could cause "an uptick in space weather events, such as solar storms, flares, and coronal mass ejections."

NASA warned that the changes in space weather could directly impact spacecraft operations and astronaut safety. They could also affect human activities on Earth, as space weather can influence power grids, GPS systems and radio communications.

Solar activity typically follows an 11-year cycle of peaks and valleys, said NASA. Earth is currently in the Solar Cycle 25, which began in 2020. The previous cycle was the weakest in over a century.

The U.S. National Oceanic and Atmospheric Administration estimates that Solar Cycle 26 is expected to begin sometime between January 2029 and December 2032.