“The sun is slowly waking up.” That’s the message from scientists who say solar activity is on the rise after 17 years of decline. This reversal means Earth could be heading into a period of stronger solar storms that threaten satellites, astronauts, and space technology.
Since the 1980s, solar activity had been steadily dropping, with fewer sunspots, flares, and coronal mass ejections during each 11-year cycle. By 2008, activity hit its lowest point in recorded history, marking the start of Solar Cycle 24.
“All signs were pointing to the sun going into a prolonged phase of low activity,” said Jamies Jasinski of NASA’s Jet Propulsion Laboratory. “So it was a surprise to see that trend reversed. The Sun is slowly waking up.”
Jasinski led research analyzing decades of data from missions observing both the sun and solar wind. The study revealed significant increases since 2008: solar wind velocity is up 6%, density has risen 26%, temperature increased 29%, and the interplanetary magnetic field strength has surged 31%.
This rise indicates stronger solar magnetic activity, which in turn produces more geomagnetic storms. These storms not only create auroras in Earth’s skies but also increase risks to satellites, astronauts, and even power grids.
Why the sun has shifted course remains unclear. Historically, the sun has undergone prolonged quiet phases, such as the Maunder Minimum (1645–1715), when fewer than 50 sunspots appeared in 70 years. That period coincided with what’s known as the “Little Ice Age,” when Northern Hemisphere winters grew exceptionally harsh, though evidence suggests volcanic activity may have played a stronger role in cooling than the sun itself.
Another quiet phase happened between 1790 and 1830, and more recently between the 1980s and 2008. Yet scientists admit these long-term fluctuations remain difficult to predict.
“The longer-term trends are a lot less predictable and are something we don’t completely understand yet,” Jasinski said.
The research findings were published on September 8 in The Astrophysical Journal Letters, offering new insight into the sun’s awakening and what it might mean for Earth in the years ahead.
