In a teleconference with reporters on Tuesday, representatives from NASA, the National Oceanic and Atmospheric Administration (NOAA), and the international Solar Cycle Prediction Panel announced that the Sun has reached its solar maximum period, which could continue for the next year.

The solar cycle is a natural cycle the Sun goes through as it transitions between low and high magnetic activity. Roughly every 11 years, at the height of the solar cycle, the Sun's magnetic poles flip — on Earth, that'd be like the North and South poles swapping places every decade — and the Sun transitions from being calm to an active and stormy state.

Visible light images from NASA's Solar Dynamics Observatory highlight the appearance of the Sun at solar minimum (left, Dec. 2019) versus solar maximum (right, May 2024). During solar minimum, the Sun is often spotless. Sunspots are associated with solar activity and are used to track solar cycle progress.

NASA and NOAA track sunspots to determine and predict the progress of the solar cycle — and ultimately, solar activity. Sunspots are cooler regions on the Sun caused by a concentration of magnetic field lines, representing the visible component of active regions, areas of intense and complex magnetic fields on the Sun that are the source of 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."

Understanding Solar Maximum and Its Impacts

The solar cycle is the natural cycle of the Sun transitioning between low and high activity. During solar maximum, the Sun can unleash immense explosions of light, energy, and solar radiation, all of which create what is known as space weather. The implications of space weather are extensive, affecting satellites and astronauts in space, as well as communications systems — such as radio and GPS — and power grids on Earth. When the Sun is most active, space weather events become more frequent. This solar activity has led to increased visibility of auroras and impacts on satellites and infrastructure in recent months.

"This announcement doesn't mean that this is the peak of solar activity we'll see this solar cycle," emphasized 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."

The specific peak of solar maximum will only be determined after a consistent decline in solar activity is observed post-peak. Nevertheless, over the past two years, the Sun has shown signs of this active phase of the solar cycle, with a consistently high number of sunspots observed. Given these patterns, scientists predict the maximum phase might last another year before the Sun begins its decline toward solar minimum. The Solar Cycle Prediction Panel, established in 1989, has been instrumental in these predictions for upcoming solar cycles.

Expectations and Observations

"Solar Cycle 25 sunspot activity has slightly exceeded expectations," asserted Lisa Upton, co-chair of the Solar Cycle Prediction Panel and lead scientist at the Southwest Research Institute in Texas. "However, despite witnessing a few large storms, they aren't larger than what we might expect during the maximum phase of the cycle."

The NOAA anticipates additional solar and geomagnetic storms during the ongoing solar maximum period. Such phenomena lead to exciting opportunities for skywatchers, particularly with sightings of brilliant auroras expected over the next several months. Although large geomagnetic storms are less frequent, significant storms can still occur during the declining phase of the solar cycle.

Preparing for Future Predictions and Research

NASA and NOAA are proactively preparing for the future of space weather research and predictions. The Parker Solar Probe, slated for its closest-ever approach to the Sun in December 2024, represents a significant leap forward in understanding space weather right from its source. Additionally, NASA is launching a series of missions over the next year aimed at enhancing our understanding of space weather and its impacts across the solar system. This research is crucial for supporting NASA's Artemis campaign, which involves spacecraft and astronauts venturing beyond low Earth orbit.

To understand how solar weather may affect Earth's conditions and technology, interested individuals can visit NOAA's Space Weather Prediction Center, which serves as the U.S. government's official source for space weather forecasts, watches, warnings, and alerts.