Solar Cycle 25 is Exceeding Predictions and Showing Why We Need the GDC Mission

December 2019 marked the beginning of Solar Cycle 25. The Sun’s activity has quickly ramped up and even though we haven’t reached peak levels in this cycle, the Sun’s activity is already exceeding predictions. Solar events will continue to increase as we near solar maximum in 2025, and our lives and technology on Earth, as well as satellites and astronauts in space, will be impacted.

NASA’s Heliophysics Division is developing a mission that will provide crucial advances in our understanding of the ionosphere-thermosphere (I-T) system – the Geospace Dynamics Constellation (GDC). This mission will provide the first coordinated global-scale observations of the I-T region, where the effects of solar activity are often seen. The I-T region is a part of Earth’s upper atmosphere that extends up to about 400 miles altitude and includes low-Earth-orbit, where the International Space Station and many commercial and governmental satellites reside. The I-T system is a region that affects our technological society in many ways, from creating interference in radio signals to generating large electric currents in power distribution systems. The GDC mission’s study of the global, coupled system will enable dramatic improvements in our space weather models, which will lead to the mitigation of negative effects on space-based, air-based, and ground-based assets.

Visualization of the Geospace Dynamics Constellation orbiting Earth. Credits: NASA
A More Active Solar Maximum

During the Sun’s natural 11-year cycle, the Sun shifts from relatively calm to stormy, then back again. At its most active, called solar maximum, the Sun is freckled with sunspots and its magnetic poles reverse. (On Earth, that would be like if the North and South Poles flip-flopped every decade.) During solar minimum, on the other hand, sunspots are few and far between. Often, the Sun is as blank and featureless as an egg yolk.

The Solar Cycle 25 Prediction Panel, an international group of experts co-sponsored by NASA and NOAA, predicted that this would be a below-average solar cycle, like the one before it – Solar Cycle 24. However, the Sun has been much more active this cycle than anticipated. The cycle is aligning more with a study from a team lead by Scott McIntosh of National Center for Atmospheric Research, published in Solar Physics.

The chart shows the number of sunspots from 1975 to 2030, represented as a green line that goes up and down, like a wave. The original prediction is at the right side of the chart as a blue line. A red line, the McIntosh Et al study is layered with it but at many points higher than the blue line.
This chart shows the original predicted number of sunspots, represented as the blue line. The green lines show the observed sunspots, which are trending toward the red line – the McIntosh et al. study – which predicts a higher number of sunspots.

With more activity comes an increase in space weather events including solar flares and solar eruptions, which can impact radio communications, electric power grids, and navigation signals, as well as pose risks to spacecraft and astronauts. We have an increasing dependence on space-based technology and ground-based infrastructure that are susceptible to the dynamic nature of space. For many new commercial and government stakeholders, this already stronger-than-expected solar cycle will be the first they navigate.

During Solar Cycle 26, the GDC mission will be able to provide valuable insight that isn’t available during this solar maximum.

An animated gif showing a spout of yellow lines flying of the Sun and impacting the Earth. The lines dissolve in the Earth's atmosphere.
Space weather impacts the ionosphere in this animation. Credits: NASA/GSFC/CIL/Krystofer Kim
Space Weather & Global Impacts

There are more than 35,000 objects orbiting in the ionosphere-thermosphere region around our planet, including the International Space Station, weather and communications satellites, and other operational government assets, with many more being launched each year. When the ionosphere-thermosphere system is pummeled by solar and geomagnetic activity, these assets are adversely affected. For example:

  • Variable satellite drag due to atmospheric heating modifies spacecraft operations and orbits. This can cause satellites to reenter Earth’s atmosphere prematurely, decrease satellite lifetimes, increase the risk of orbital collisions, and cause spacecraft to be out of optimal position for their mission.
  • Radiofrequency communication and navigation capabilities are degraded.
      • GPS positioning experiences errors due to the ionospheric disturbances (in plasma density) that occur on regional scales (a continent or larger).
      • Space-to-surface transmission noise is increased. This affects military monitoring of the north polar region and communications globally.
  • During times of geomagnetic activity, the near-polar regions experience high fluxes of radiation in the form of energetic particles. These particles can travel to low altitudes, where they become a concern for airplane flight crew and passenger health.
  • When intense electrical currents driven by space weather flow overhead in the I-T system, they can produce enormous “mirror” currents in power lines and pipelines. These currents can damage or destroy critical infrastructure, leading to expensive power outages or maintenance and repair costs.

The key to making dramatic improvements in our ability to predict and mitigate such events lies in finally understanding Earth’s ionosphere-thermosphere system. This is the heart of the local space environment: all processes active in near-Earth space start, end, or are modified there. Despite its importance, this transition region is the aspect of Earth’s space environment that is least understood as a global system.

It is necessary to prioritize missions that will improve on the lack of measurements in the ionosphere-thermosphere system to better mitigate space weather impacts on national infrastructure and support the national needs of the operational agencies. Recent events have highlighted the need to observe and better understand the variable density and drag that satellites encounter. With real-time data from a mission like GDC, mission operators can better protect satellites affected by space weather activity.

NASA’s Space Weather Program will provide a framework to ensure that the GDC data can be quickly ingested into operational systems in partnership with NOAA and other agencies. The NASA Space Weather Program will provide the needed modeling support for satellite operations and facilitate the real-time downlink capability for appropriate space-based platforms. Additionally, the NASA Space Weather Program will facilitate coordination with partner agencies to incorporate their complementary ground-based measurements throughout the solar cycle.

By Nicola Fox, Director of NASA’s Heliophysics Division

Solar Flares FAQs

Have questions about solar flares? Find answers here!

What is a solar flare?
A solar flare is an intense burst of radiation, or light, on the Sun. Flares are our solar system’s most powerful explosive events – the most powerful flares have the energy equivalent of a billion hydrogen bombs, enough energy to power the whole world for 20,000 years

Light only takes about 8 minutes to travel from the Sun to Earth, so that’s how long it would take the energy from a flare to reach our planet. 

How do solar flares affect Earth?
Solar flares only affect Earth when they occur on the side of the Sun facing Earth. Solar flares are rated into different classes based on their strength, or energy output, and the effect a flare will have on Earth depends on what class it is (B, C, M, and X classes, with X being the most intense). Learn more about flare classes here:

Earth’s atmosphere absorbs most of the Sun’s intense radiation, so flares are not directly harmful to humans on the ground. However, the radiation from a flare can be harmful to astronauts outside of Earth’s atmosphere, and they can affect the technology we rely on.

Stronger solar flares – those rated class M5 or above – can have impacts on technology that depends on Earth’s ionosphere, our electrically charged upper atmosphere, like high-frequency radio used for navigation and GPS. When the burst of light from a flare reaches Earth, it can cause surges of electricity and scintillation, or flashes of light, in the ionosphere, leading to radio signal blackouts that can last for minutes or, in the worst cases, hours at a time. One risk of a radio blackout is that radios are often used for emergency communications, for instance, to direct people amid an earthquake or hurricane.

What is the difference between a solar flare and a coronal mass ejection (CME)?
Solar flares and coronal mass ejections (CMEs) both involve gigantic explosions of energy, but are otherwise quite different. Solar flares are bright flashes of light, whereas CMEs are giant clouds of plasma and magnetic field. The two phenomena do sometimes occur at the same time – indeed the strongest flares are almost always correlated with coronal mass ejections – but they emit different things, they look and travel differently, and they have different effects near planets.

Here’s more on the difference between a solar flare and a CME:

How big are solar flares?
Flares tend to come from active regions on the Sun several times the size of Earth or more.

An image of the Sun, with a flare exploding. Earth is shown to scale, smaller than the flare.
NASA’s Solar Dynamics Observatory captured an image of a mid-level solar flare on March 11, 2015, seen as a bright flash of light on the left side of the Sun. This image is a blend of two wavelengths of light – 171 and 131 angstroms – typically colorized in gold and teal, respectively.
Credits: NASA/SDO

How long do solar flares last?
Solar flares can last from minutes to hours. Sometimes the same active region on the Sun can give rise to several flares in succession, erupting over the course of days or even weeks.

What causes solar flares?
Solar flares erupt from active regions on the Sun – places where the Sun’s magnetic field is especially strong and turbulent. Active regions are formed by the motion of the Sun’s interior, which contorts its own magnetic fields. Eventually, these magnetic fields build up tension and explosively realign, like the sudden release of a twisted rubber band, in a process known as magnetic reconnection. This rapid energy transfer creates solar flares as well as other kinds of solar eruptions like coronal mass ejections and solar energetic particle events.

Do flares occur on other stars?
Yes! Flares occur on most if not all types of stars (although in that case they’re called “stellar” rather than “solar” flares). In fact, flares from other stars are frequently more severe – both stronger and more frequent – than those produced by the Sun. 

How often do solar flares occur?
Like earthquakes, the frequency of solar flares depends on their size, with small ones erupting more often than big ones. The number of flares also increases as the Sun nears solar maximum, and decreases as the Sun nears solar minimum. So, throughout the 11-year solar cycle, flares may occur several times a day or only a few times per month.

How do we study solar flares?
We study flares by detecting the light they emit. Flares emit visible light but they also emit at almost every wavelength of the electromagnetic spectrum. Flares also shoot out particles (electrons, protons, and heavier particles) that spacecraft can detect.

Scientists used ground- and space-based sensors and imaging systems to study flares. NASA operates a suite of Heliophysics missions, utilizing its entire fleet of solar, heliospheric, and geospace spacecraft to discover the processes at work throughout the space environment. 

NASA heliophysics missions on a background of the Earth and Sun, showing their location in the solar system.
This graphic represents NASA’s Heliophysics Fleet as of March 2022. Credit: NASA

NASA also works with other agencies to study and coordinate space weather activities. The Committee on Space Weather, which is hosted by the Office of the Federal Coordinator for Meteorology, is a multiagency organization co-chaired by representatives from NASA, the National Oceanic and Atmospheric Administration (NOAA), the United States Department of Defense, and the National Science Foundation and functions as a steering group responsible for tracking the progress of the National Space Weather Program.

Can we predict when a solar flare will occur?
We cannot yet predict when a specific solar flare will occur, but we can measure several factors that make a flare more likely to occur. Flares erupt from active regions, where the Sun’s magnetic field becomes especially intense, so we monitor the Sun’s magnetic activity and when an active region forms, we know a flare is more likely. On longer timescales, the Sun goes through periodic variations or cycles of high and low activity that repeat approximately every 11 years, known as the solar cycle. Solar minimum refers to the period when the number of sunspots is lowest and solar activity, including flares, is lower; solar maximum occurs in the years when sunspots are most numerous and flares are more common. 

Who is responsible for tracking and sending alerts when there is solar activity
NOAA’s Space Weather Prediction Center (SWPC) is the nation’s official source of space weather alerts, watches, and warnings. It provides real-time monitoring and forecasting of solar and geophysical events. SWPC is part of the National Weather Service and is one of the nine National Centers for Environmental Prediction.

By Miles Hatfield
NASA’s Goddard Space Flight Center, Greenbelt, Md.

Sun Releases Strong Solar Flare

The Sun emitted a strong solar flare on May 3, 2022, peaking at 9:25 a.m. EDT. NASA’s Solar Dynamics Observatory, which watches the Sun constantly, captured an image of the event.

A golden Sun with a flare erupting from the bottom left
NASA’s Solar Dynamics Observatory captured this image of a solar flare – as seen in the bright flash in the bottom left portion of the image – on May 3, 2022. The image shows a subset of extreme ultraviolet light that highlights the extremely hot material in flares and which is colorized in yellow.

Solar flares are powerful bursts of energy. Flares and solar eruptions can impact radio communications, electric power grids, navigation signals, and pose risks to spacecraft and astronauts.

This flare is classified as an X-class flare. X-class denotes the most intense flares, while the number provides more information about its strength. More info on how flares are classified can be found here.

To see how such space weather may affect Earth, please visit NOAA’s Space Weather Prediction Center https://spaceweather.gov/, the U.S. government’s official source for space weather forecasts, watches, warnings, and alerts. NASA works as a research arm of the nation’s space weather effort. NASA observes the Sun and our space environment constantly with a fleet of spacecraft that study everything from the Sun’s activity to the solar atmosphere, and to the particles and magnetic fields in the space surrounding Earth.

Strong Solar Flare Erupts from Sun

The Sun emitted a strong solar flare on April 30, 2022, peaking at 9:47 a.m. EDT. NASA’s Solar Dynamics Observatory, which watches the Sun constantly, captured an image of the event.

a red Sun, with a golden flare bursting from the top right.
NASA’s Solar Dynamics Observatory captured this image of a solar flare – as seen in the bright flash in the upper right portion of the image – on April 30, 2022. The image shows a subset of extreme ultraviolet light that highlights the extremely hot material in flares and which is colorized in red.

Solar flares are powerful bursts of energy. Flares and solar eruptions can impact radio communications, electric power grids, navigation signals, and pose risks to spacecraft and astronauts.    

This flare is classified as an X-class flare. X-class denotes the most intense flares, while the number provides more information about its strength. More info on how flares are classified can be found here.

To see how such space weather may affect Earth, please visit NOAA’s Space Weather Prediction Center https://spaceweather.gov/, the U.S. government’s official source for space weather forecasts, watches, warnings, and alerts. NASA works as a research arm of the nation’s space weather effort. NASA observes the Sun and our space environment constantly with a fleet of spacecraft that study everything from the Sun’s activity to the solar atmosphere, and to the particles and magnetic fields in the space surrounding Earth.