We will get a better look at our sun than ever before as our closest star enters its 25th solar cycle since observations began in earnest, according to scientists from NASA and the National Oceanic and Atmospheric Administration (NOAA).
Numerous public efforts from the American space agencies – a live panel, a Reddit discussion and a detailed press release – discussed the 11-year solar cycle and its impact on our planet’s inhabitants.
The solar cycle is the period of time between solar minimum, when there are fewer sunspots and less solar activity such as ejections of charged particles, and the solar maximum. The start of the new solar cycle was determined by looking at monthly data on sunspots from the Royal Observatory of Belgium’s World Data Center for the Sunspot Index and Long-term Solar Observations, NASA said in the release. The solar maximum is predicted for July 2025, based on this data.
Scientists are interested in learning about what drives our star’s activity to better protect Earth infrastructure from solar events, which can include these particles hitting satellites or power lines and shorting our services – just like what happened in Quebec in 1989.
Satellites can be damaged when energetic particles cause surface and dielectric charging, building up on electronics and solar panels and causing damage. Meanwhile, geomagnetic storms in the atmosphere cause increased atmospheric heat that can induce currents in power lines and pipelines, putting the power grid at risk.
Fortunately, two missions are gazing closer at the sun than ever before, as NASA’s Parker Solar Probe (launched in 2018 and gathering data) and the European Space Agency’s Solar Orbiter (launched in 2020 and preparing for science observations still) make periodic passes by the star. Solar Orbiter will provide the first look at the sun’s poles, while Parker makes daring dips inside the orbit of Mercury to look at solar structures from up close.
“We can actually, even though it’s hard to do, we can send missions right up close to our star,” said Nicola Fox, NASA’s heliophysics division director, in a live streamed discussion Tuesday (Sept. 15). “We can really study its impact. We can study how the activity changes, how it impacts our planet, how it impacts well beyond our planet. And of course, how it shapes our place in the universe, as we are orbiting the Milky Way.”
NASA and NOAA are frequent collaborators on space mission to protect Earth, and for that reason a NOAA representative pointed to how the agencies are preparing for the next solar maximum in about six years. (For example, instruments on spacecraft like NOAA’s GOES series look at the sun’s irradiance, structure of the sun’s atmosphere, its magnetic activity and its outer atmosphere.)
“Solar activity manifests in various explosive waves – solar flares – which are bursts of electromagnetic energy coming from the sun, and these are often accompanied by energetic particles that can travel about half the speed of light,” Elsayed Talaat, NOAA’s director of the office of projects, planning, and analysis for NOAA’s Satellite and Information Service, said in the same discussion.
“These are both explosions of plasma and magnetic field from the sun’s outer atmosphere, the corona, and they [the explosions] can inject billions of tons of coronal material at time at millions of miles per hour into interplanetary space. All of these events can impact technological society in space, commerce and exploration.”
Canadians in particular are dependent upon satellite communications and Earth observations for matters ranging from cell phone calls to disaster relief to, in the most remote areas, Internet connections. So by making better predictions of solar activity, it allows scientists to take measures such as predicting which satellites could be in the way of the next eruption.
Satellite customers can be quickly shifted to other machines, allowing those satellites at risk to be put into a safe mode to ride out the storm, for example. Power companies on the ground worried about their infrastructure could be warned ahead of time of surges from solar activity, making it easier to deploy power appropriately during solar events.
“There are regulations within the U.S. power industry to evaluate the impacts of an extreme space weather event, and where necessary, mitigate those impacts so that the reliability and availability of electric power is maintained,” said Robert Rutledge, lead of operations at the NOAA Space Weather Prediction Center, in the Reddit discussion. “So while a great deal of work remains to fully understand and fully mitigate the impacts of space weather, great progress is underway.”
Some solar activity is extremely dangerous, with the most notorious being the Carrington event in 1859 that wreaked havoc on telegraphic systems of the day. A similar solar explosion aimed at Earth today would be dangerous for satellites, the electrical grid and numerous other systems. In 2012, scientists observed a huge solar event that fortunately for Earth, blasted off to the side of the sun and didn’t come near our planet. Panellists at the NASA-NOAA live event said our planet missed the explosion by nine days, and that was a fortunate thing.
“When we did the modeling, we saw it was actually much bigger even than the Carrington event that had happened 150 years before,” Fox said in the livestreamed discussion. “We know that they [solar events] are happening. It’s just [a question of] whether or not … Earth is going to be in the path for them. So yes, we’re certainly overdue for one to come straight towards us. We are seeing big events on the sun much more frequently. And of course, now that we have so many more measurements in space, it just means that we will be able to observe them, whereas before we would miss it because it didn’t impact the Earth.”
On Reddit, a solar scientist added that while more of our infrastructure is vulnerable to solar events, on the other hand, we also know far more about the sun than back when the Carrington event occurred.
“We are much more prepared for a Carrington-level event than they were in the 1800s,” said Laurel Rachmeler, a solar scientist at NOAA’s National Centers for Environmental Information in Boulder, Colorado. “In fact, that event was a big part of the reason we know that there can be effects on Earth from things that happen on the sun. Since then, we have learned a lot about the sun and are able to monitor it for oncoming events. We have precautions, plans, and procedures in place to avoid the worst effects here on Earth.”
“If a Carrington-type event happened,” added Dan Seaton, solar physicist at the University of Colorado and NOAA’s National Centers for Environmental Information, “the first sign we’d have of it would be a large and rapid increase in the X-ray and extreme ultraviolet radiation we receive from the sun. That increase in radiation affects the Earth’s upper atmosphere and ionosphere, disrupting radio communications and potentially causing drag on satellites in low orbits. Energetic particles that can be dangerous to astronauts can arrive as soon as a few minutes later. Really energetic solar eruptions can travel to the Earth in about half a day, so the geomagnetic effects that can be harmful to power grids come with a bit more warning.”
While scientists are preparing for the worst, the Solar Cycle 25 Prediction Panel says that this solar cycle should have sunspots a little bit below average, but observations are always ongoing to refine the predictions, officials said in the Reddit discussion.
NASA is also concerned about protecting the safety of its astronauts, especially as the agency – in partnership with Canada and other nations – moves to the Moon and possibly, in the 2030s or so, to Mars. The Moon has no substantial magnetic field to protect astronauts from solar radiation, so they are more exposed there than they would be on Earth.
NASA plans to land astronauts at the Moon’s south pole in 2024, as part of the Artemis program. Canada’s contribution will be providing the Canadarm3 robotic arm to a future lunar-area space station called Gateway. Gateway will also be host to many scientific payloads, with some of the first ones planned including experiments to measure space weather and heliophysics environmental conditions near the Moon – providing an important comparison point to what scientists observe near Earth, NASA’s chief exploration scientist said.
“These astronauts, on these trips, they’re going to be exposed to time periods where they are outside of the Earth’s magnetic field,” said Jacob Bleacher, the chief exploration scientist, in the livestreamed discussion.
“For us, it’s really important to understand what the sun is doing. What is it doing under normal conditions? What is it doing when unique events are occurring? Because if we can understand that, we can predict, prepare and mitigate … what the sun is going to do, what the environment is going to be. It helps us protect our astronauts and our hardware.”
Even ordinary people can watch the action, NASA officials said, through looking at data from NASA’s Solar Dynamics Observatory (SDO), the Solar and Heliospheric Observatory (SOHO) and other missions. While NASA didn’t mention this in their discussion, one concern among scientists is the age of these venerable and useful observatories. SDO launched in 2010 and SOHO launched in 1995. While both remain in good health, satellites do need to be periodically changed out as components age and fuel runs low.
Fortunately, NOAA’s Space Weather Follow-On Mission (SWFO-L1) is planned to launch in 2024, sharing a ride with NASA’s Interstellar Mapping and Acceleration Probe. The NOAA mission will gather data from the solar wind, as well as images of the corona, to further assist with space weather. The mission will also be perched at a Lagrange point, or stable area between two large bodies in space, to minimize fuel usage, which should help it last for a long time.
While scientists are of course concerned with the power of the sun, they also said that the star’s workings still inspire awe in them even though they work with the huge scale day by day.
“No one tells you that you never really get used to the scales involved in solar and space weather,” Rachmeler added on Reddit. “The sun is so big, it is hard to wrap your head around, and every time I try to translate it into units that my brain can understand, I am surprised. The energy released by a typical coronal mass ejection (or CME) is many many times the amount of energy the entire human race use in a year. The highest resolution digital images taken of the corona have pixels that are just under 100 km, or 62 miles, across! For me, that is small-scale.”
- Follow @SpaceWeather on Twitter