New NASA findings indicate that potentially dangerous solar storm activity has been ramping up over the last two decades, suggesting a longer-term deviation beyond the known 11-year solar cycles.
Before 2008, data collected since the 1980s indicated a notable lull in solar activity, which has since reversed itself. Solar flares, solar storms, and coronal mass ejections are examples of the types of increasing disturbances that could have detrimental effects for us on Earth.
Now, a new paper presented in The Astrophysical Journal Letters finds that these events are occurring with increased frequency.
A History of Solar Storms
Generated by particularly strong magnetic activity, sunspots are darkened, cooler points on the solar surface. The spots are often concurrent with events that may be of concern across the solar system, such as the sudden bursts of radiation called solar flares and the enormous plasma bubbles known as coronal mass ejections.
Since the 1600s, astronomers have long noted the Sun’s turbulent nature. Galileo and other astronomers of that era observed sunspots and recorded how they changed over time. Those astronomers identified a period from 1645 to 1715 during which solar activity significantly diminished. Another quiet spell began in 1790 and lasted all the way through to 1830.
“We don’t really know why the Sun went through a 40-year minimum starting in 1790,” said lead author Jamie Jasinski of NASA’s Jet Propulsion Laboratory in Southern California. “The longer-term trends are a lot less predictable and are something we don’t completely understand yet.”
Modern Data Reveals a New Trend
Continuing into modern times, advanced tools have enabled a closer and more precise investigation of such occurrences as sunspots and solar flares, which had been in decline for some time. The extended period of decline that lasted up until 2008 was so severe that researchers called it a “deep solar minimum,” which they expected to be only the beginning of a period of low activity.
“All signs were pointing to the Sun going into a prolonged phase of low activity,” Jasinski said. “So it was a surprise to see that trend reversed. The Sun is slowly waking up. But then the trend of declining solar wind ended, and since then plasma and magnetic field parameters have steadily been increasing.”
Jasinski’s team identified the trend from publicly available data collected at NASA’s OMNIWeb Plus platform. The two primary sources for the data were NASA’s ACE and Wind missions, both launched in the 1990s. Analyzing the data made clear a significant upturn in solar storms, which can bring their destructive events across space.
Tracking Space Weather
These space weather events travel across the solar system on journeys that may eventually bring them to Earth or come into contact with our near-Earth orbital infrastructure. Their electromagnetic natures can cause interference with power grids, communications networks, GPS systems, and spacecraft. With our modern computerized society’s reliance on these systems and the threats to astronauts’ direct safety, NASA tracks these space weather events.
Additionally, the space agency is pursuing continued research into how they affect the space environment as part of the Artemis campaign, aimed at long-term habitation beyond Earth, beginning with the Moon. Toward this end, NASA is launching the Interstellar Mapping and Acceleration Probe (IMAP) and the Carruthers Geocorona Observatory missions, which will be supplemented by the National Oceanic and Atmospheric Administration’s Space Weather Follow-On-Lagrange-1 (SWFO-L1), all set to commence in the near future.
While increasing solar activity should concern us, NASA is keeping a close eye on the issue. The data from these instruments is expected to aid scientists as we return to the Moon during missions that will precede eventual crewed missions to Mars, as well as future missions to even further destinations.
The paper, “The Sun Reversed Its Decades-long Weakening Trend in 2008,” appeared in The Astrophysical Journal Letters on September 8, 2025.
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.