NASA and NOAA have declared the Sun’s solar maximum, noting increased sunspot activity and heightened solar events that influence Earth’s space weather.
This period is linked to significant geomagnetic storms and aurora displays, with potential disruptions to satellites and communication systems.
Solar Maximum Announced by NASA and NOAA
During a teleconference on Tuesday, officials from NASA, the National Oceanic and Atmospheric Administration (NOAA), and the international Solar Cycle Prediction Panel declared that the Sun has entered its solar maximum period. This phase, characterized by heightened magnetic activity, could continue for the next year.
The solar cycle is an approximately 11-year period during which the Sun oscillates between periods of low and high magnetic activity. At the cycle’s peak, the Sun undergoes a magnetic flip where its magnetic poles reverse positions—akin to Earth’s North and South poles switching places every decade. This transition marks the shift from a quieter phase to one of intense activity and frequent solar storms.
Sunspot Monitoring and Solar Activity
To monitor and forecast the stages of the solar cycle, and ultimately, solar activity, NASA and NOAA track sunspots, which are cooler areas on the Sun’s surface. These spots arise from concentrated magnetic fields and are key indicators of the Sun’s more active regions. These regions of intense and complex magnetic fields are not only visually striking but are also the origins of powerful solar eruptions.
“During solar maximum, the number of sunspots, and therefore, the amount of solar activity, increases,” said Jamie Favors, director, Space Weather Program at NASA Headquarters in Washington. “This increase in activity provides an exciting opportunity to learn about our closest star — but also causes real effects at Earth and throughout our solar system.”
The solar cycle is the natural cycle of the Sun as it transitions between low and high activity. During the most active part of the cycle, known as solar maximum, the Sun can unleash immense explosions of light, energy, and solar radiation — all of which create conditions known as space weather. Space weather can affect satellites and astronauts in space, as well as communications systems — such as radio and GPS — and power grids on Earth. Credit: Beth Anthony/NASA
Effects of Solar Activity on Earth
Solar activity strongly influences conditions in space known as space weather. This can affect satellites and astronauts in space, as well as communications and navigation systems — such as radio and GPS — and power grids on Earth. When the Sun is most active, space weather events become more frequent. Solar activity has led to increased aurora visibility and impacts on satellites and infrastructure in recent months.
During May 2024, a barrage of large solar flares and coronal mass ejections (CMEs) launched clouds of charged particles and magnetic fields toward Earth, creating the strongest geomagnetic storm at Earth in two decades — and possibly among the strongest displays of auroras on record in the past 500 years.
From May 3 through May 9, 2024, NASA’s Solar Dynamics Observatory observed 82 notable solar flares. The flares came mainly from two active regions on the Sun called AR 13663 and AR 13664. This video highlights all flares classified at M5 or higher with nine categorized as X-class solar flares. Credit NASA’s Goddard Space Flight Center
Solar Maximum’s Duration and Peak
“This announcement doesn’t mean that this is the peak of solar activity we’ll see this solar cycle,” said Elsayed Talaat, director of space weather operations at NOAA. “While the Sun has reached the solar maximum period, the month that solar activity peaks on the Sun will not be identified for months or years.”
Scientists will not be able to determine the exact peak of this solar maximum period for many months because it’s only identifiable after they’ve tracked a consistent decline in solar activity after that peak. However, scientists have identified that the last two years on the Sun have been part of this active phase of the solar cycle, due to the consistently high number of sunspots during this period. Scientists anticipate that the maximum phase will last another year or so before the Sun enters the declining phase, which leads back to solar minimum. Since 1989, the Solar Cycle Prediction Panel — an international panel of experts sponsored by NASA and NOAA — has worked together to make their prediction for the next solar cycle.
Historical Perspective on Solar Cycles
Solar cycles have been tracked by astronomers since Galileo first observed sunspots in the 1600s. Each solar cycle is different — some cycles peak for larger and shorter amounts of time, and others have smaller peaks that last longer.
“Solar Cycle 25 sunspot activity has slightly exceeded expectations,” said Lisa Upton, co-chair of the Solar Cycle Prediction Panel and lead scientist at Southwest Research Institute in San Antonio, Texas. “However, despite seeing a few large storms, they aren’t larger than what we might expect during the maximum phase of the cycle.”
The most powerful flare of the solar cycle so far was an X9.0 on October 3 (X-class denotes the most intense flares, while the number provides more information about its strength).
NOAA anticipates additional solar and geomagnetic storms during the current solar maximum period, leading to opportunities to spot auroras over the next several months, as well as potential technology impacts. Additionally, though less frequent, scientists often see fairly significant storms during the declining phase of the solar cycle.
Future of Space Weather Research and Predictions
NASA and NOAA are preparing for the future of space weather research and prediction. In December 2024, NASA’s Parker Solar Probe mission will make its closest-ever approach to the Sun, beating its own record of closest human-made object to the Sun. This will be the first of three planned approaches for Parker at this distance, helping researchers to understand space weather right at the source.
NASA is launching several missions over the next year that will help us better understand space weather and its impacts across the solar system.
Space Weather Research Supporting Artemis Campaign
Space weather predictions are critical for supporting the spacecraft and astronauts of NASA’s Artemis campaign. Surveying this space environment is a vital part of understanding and mitigating astronaut exposure to space radiation.
NASA works as a research arm of the nation’s space weather effort. To see how space weather can affect Earth, please visit NOAA’s Space Weather Prediction Center, the U.S. government’s official source for space weather forecasts, watches, warnings, and alerts.