Since December 2019, the sun has been moving towards a more active part of its cycle, when increasingly intense energy pulses can shoot in all directions. Some of these large explosions of charged particles are heading toward Earth. Without a good way to anticipate these solar storms, we are vulnerable. A big one could pull a series out of our communication systems and power grids before we knew what had hit us.
An almost recent loss occurred in the summer of 2012. A gigantic solar storm launched a radiation-filled spot in the direction of the Earth at more than 9 million kilometers per hour. The potentially debilitating explosion quickly traversed nearly 150 million kilometers toward our planet and would have reached Earth if it had arrived just a week earlier. Scientists learned of this after the fact, just because it hit a NASA satellite designed to monitor this type of space-time.
That 2012 storm was the one most researchers measured since 1859. When a powerful storm hit the northern hemisphere in September of that year, people were not so lucky. Many telegraph systems throughout Europe and North America failed and electrified lines shocked some telegraph operators. It became known as the Carrington event, named after British astronomer Richard Carrington, who witnessed intense lights of light in the sky and recorded what he saw.
The world has advanced far beyond telegraphic systems. A Carrington-level impact would bring down satellites today, disrupting GPS, cell phone networks and internet connections. Banking systems, aviation, trains and traffic signals would also be successful. Damaged electrical networks would take months or more to repair.
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Especially now, during a pandemic that makes many of us dependent on Zoom and other video communications programs to work and attend school, it’s hard to imagine the widespread disorder such an event would create. In a worse scenario conceived before the pandemic, researchers estimated that the economic toll in the United States could reach trillions of dollars, according to a 2017 review in Risk Analysis.
To prevent that destruction, in October, then-President Donald Trump signed a bill that will support research to produce better space weather forecasts and assess potential impacts and allow for better coordination between agencies like NASA and the National Oceanic and Atmospheric Administration.
"We understand a little bit about how these solar storms form, but we can't predict them (" well), "says atmospheric and space scientist Aaron Ridley of the University of Michigan at Ann Arbor. Just as scientists know how to map the probable path of tornadoes and hurricanes, Ridley hopes to see the same capabilities to predict space-time.
The ideal scenario is to receive warnings long before a storm disables satellites or landslides, and possibly even before the sun sends charged particles in our direction. With prior warning, utilities and governments could disconnect networks and take satellites out of danger.
Ridley is part of an American collaboration that creates solar storm simulations to help scientists predict quickly and accurately where storms will go, how intense they will be, and when they may affect major Earth satellites and power grids. Considering the devastation that an extreme solar storm could cause, many scientists and governments want to develop better forecasts as soon as possible.
Refluxes and flows
When scientists talk about space-time, they usually refer to two things: the solar wind, a constant flow of charged particles flowing from the sun, and coronal mass ejections, huge explosions of charged particles or plasma, ejected from the outer layers of the sun ( SN Online: 3/7/19). Other phenomena, such as high-energy particles called cosmic rays, also count as space-time, but do not cause much concern.
Coronal mass ejections, or CME, the most threatening type of solar storm, are not always harmful: they eventually generate stunning aurora generators. But given the risks of a storm shutting down key military and commercial satellites or harming the health of orbiting astronauts, it’s understandable that scientists and governments are concerned.
Astronomers have been looking at our solar companion for centuries. In the 17th century, Galileo was one of the first to spy on sunspots, slightly colder areas on the surface of the sun with strong magnetic fields that are often precursors to more intense solar activity. His successors later noticed that sunspots often produce radiation explosions called solar flares. The complex and magnetic magnetic field of the sun sometimes causes plasma filaments or loops thousands of miles in diameter to come out of the outer layers of the sun. This type of solar flare can generate CME.
“The sun’s magnetic field lines can become complicated and twisted as they suffocate in certain regions,” says Mary Hudson, a physicist at Dartmouth College. Those lines can break like a rubber band and throw a large piece of crown into interplanetary space.
It was 19th-century German astronomer Samuel Heinrich Schwabe who realized that solar activity ebbs and flows for 11-year cycles. This is because the sun’s magnetic field rotates completely every 11 years. The most recent solar cycle ended in December 2019 and we came out of the nadir of solar activity as we headed towards the peak of cycle 25 (astronomers began numbering solar cycles in the 19th century). Solar storms, especially dangerous CMEs, are becoming more frequent and intense and should reach their peak between 2024 and 2026.
Solar storms develop from the sun’s complex magnetic field. The sun rotates faster at its equator than at its poles, and since it is not a solid sphere, its magnetic field constantly rolls and spins around. At the same time, the heat inside the sun rises to the surface, with charged particles bringing new magnetic fields with it. The most intense CMEs usually come from the most vigorous period of a particularly active solar cycle, but there are many variations. The 1859 CME originated from a fairly modest solar cycle, Hudson notes.
A CME has several components. If the CME is on a trajectory toward Earth, the first thing that arrives – just eight minutes after rising from the sun – is the electromagnetic radiation, which moves at the speed of light. CMEs often produce a shock wave that accelerates electrons at extremely fast speeds, and these reach 20 minutes of light. These energy particles can damage the electronics or solar cells of satellites in high orbits. Those particles could also damage any astronaut outside the Earth’s protective magnetic field, including any of the moon. However, a crew aboard the International Space Station, within the Earth's magnetic field, would be very safe.
But the biggest threat to a CME: its giant plasma cloud, which can be millions of miles wide, usually takes between one and three days to reach our planet, depending on how fast the sun propelled the particle shotgun toward we. The Earth’s magnetic field, our first defense against space-time and space radiation, can protect us from both. Satellites and ground-based observations have shown that charged particles from a CME interact and distort the magnetic field. These interactions can have two important effects: producing more intense electric currents in the upper atmosphere, and shifting these stronger currents from the poles to places with more people and more infrastructure, Ridley says. With an extremely powerful storm, it is these potentially massive currents that put satellites and power grids at risk.
SDO / Goddard / NASA / Flickr
Anyone who relies on long-range radio or telecommunications signals may have to dispense with them until the storm blows and damaged satellites are repaired or replaced. A powerful storm can also disrupt aircraft in flight, as pilots lose contact with air traffic controllers. Although these are temporary effects, which usually last up to a day, the impacts on power grids can be worse.
A massive CME could suddenly and unexpectedly conduct kiloamp currents instead of the usual amplifiers through the wires of the power grid on Earth, overwhelming transformers and causing them to melt or explode. The entire province of Quebec, with nearly 7 million people, suffered a power outage that lasted more than nine hours on March 13, 1989, thanks to a CME during a particularly active solar cycle. The CME also affected New England and New York. If power grid operators knew what was coming, they could have reduced the flow of power on power lines and interconnections and set up backup generators where needed.
But planners need a lot more than they get today. Perhaps in the next decade, improved computer modeling and new space-time control capabilities will allow scientists to predict solar storms and their likely impacts more accurately and earlier, says physicist Thomas Berger, executive director of Space Weather Technology, Research and Education Center of the University of Colorado Boulder.
Space meteorologists classify solar storms, based on perturbations of the Earth's magnetic field, on a five-level scale, such as hurricanes. But unlike those tropical storms, the likely arrival of a solar storm is not precisely known using the available satellites. For storms that occur on Earth, the National Weather Service has access to constantly updated data. But spatial weather data is too scarce to be very useful, with few storms to monitor and provide data.
Two U.S. space-time-controlling satellites are NASA's ACE spacecraft, which dates back to the 1990s and should continue to collect data for a few more years, and NOAA's DSCOVR, which was designed at a similar time but not launched until 2015. Both orbit around of 1.5 million kilometers above Earth, which seems very far away but is barely above our planet from the perspective of a solar storm. Both satellites can only detect and measure a solar storm when its impact is imminent: 15 to 45 minutes. That’s more like “nowcasting” than forecasting, offering little more than a warning to prepare for impact.
“That’s one of the big challenges of space-time: predicting the magnetic field of a CME long before it arrives (here) so it can prepare for the incoming storm,” Berger says. But aging satellites like SOHO, a satellite launched by NASA and the European Space Agency in 1995, in addition to ACE and DSCOVR monitor only a limited range of directions that do not include the sun’s poles, leaving a large gap in observations, he says.
Ideally, scientists could predict a solar storm before it goes into space. That would give enough delivery time – more than a day – for power grid operators to protect the transformers from surges and satellites and astronauts could get out of the damage if possible.
This requires collecting more data, especially from the outer layers of the sun, in addition to better estimating when a CME will explode and whether it is expected to arrive with a bang or a moan. To help with this research, NOAA scientists will equip their next space weather satellite, scheduled for early 2025, with a coronograph, an instrument used to study the outermost part of the sun's atmosphere, the corona, while blocking most of sunlight. which would otherwise blind his vision.
A second major improvement could come just two years later, in 2027, with the launch of ESA’s Lagrange mission. It will be the first space meteorological mission to launch one of its spacecraft to a single point: 60 degrees behind the Earth in its orbit around the sun. Once in position, the spacecraft will be able to see the surface of the sun from the side before the sun’s face rotates and points in the direction of the Earth, says Juha-Pekka Luntama, head of ESA’s Office of Space Meteorology.
In this way, Lagrange will be able to monitor an active, sunny area of the sun days earlier than other spacecraft, managing to fix the speed and direction of a new solar storm earlier to allow scientists to make a more accurate forecast. With these new satellites, there will be more spacecraft observing incoming space time from different points, giving scientists more data to make predictions.
WMAP / NASA scientific team
WMAP / NASA scientific team
Meanwhile, Berger, Ridley, and colleagues focus on developing better computer simulations and models of the behavior of the sun’s crown and the ramifications of CMEs on Earth. Ridley and his team are creating a new software platform that allows researchers from anywhere to quickly upgrade models of the upper atmosphere affected by space climate. Ridley’s group is also modeling how a CME shakes our planet’s magnetic field and releases charged particles down to earth.
Berger also collaborates with other researchers in modeling and simulating the Earth’s upper atmosphere to better predict how solar storms affect its density. When a storm strikes, it compresses the magnetic field, which can change the density of the outer layers of the Earth's atmosphere and affect the amount of drag that satellites have to fight to stay in orbit.
There have been some cases of satellites damaged by solar storms. The Japanese satellite ADEOS-II ceased operation in 2003, after a period of intense bursts of solar energy. And the Solar Maximum Mission satellite appeared to be dragged into lower orbit and burned into the atmosphere after the same 1989 solar storm that left Quebec in the dark.
Satellites affected by solar storms may also run the risk of colliding with each other or space debris. With mega-constellations of satellites like SpaceX launched by the hundreds (SN: 28/03/20, p. 24), and with tens of thousands of satellites and bits of space flotation already in crowded orbits, the risks are real of something deriving in the way of something else. Any space crash will also create more space junk, throwing debris that also puts spaceships at risk.
They are all strong motivators for Ridley, Berger, and their colleagues to study how storm-induced drag works. The U.S. military is tracking satellites and debris and predicting where they will be in the future, but all those calculations are worthless without knowing the effects of solar storms, says Boris Krämer, an aerospace engineer at the University of California, San Diego who collaborates with Ridley. “To put satellites on trajectories to avoid collisions, you have to know space-time,” Krämer says.
It takes time to create simulations by estimating the drag on a single satellite. Current models run on powerful supercomputers. But if a satellite needs to use its on-board computer to do those calculations on the fly, researchers need to develop sufficiently accurate models that run much faster and with less power.
New data and new models probably won’t be online in time for the next solar storm season, but they should be in place for solar cycle 26 in the 2030s. Maybe by then, scientists will be able to give earlier red alerts. to warn of an incoming storm, giving more time to move satellites, buttress transformers and avoid the worst.
The goal of improving space weather forecasts has attracted the support and interest of the federal government from industry, including Lockheed Martin, due to threats to major satellites, including the 31 that make up the U.S. GPS network.
The growing interest in space time has led to the 2020 law, known as the Promote Research and Observations of Space Weather to Improve the Forecasting of Tomorrow Act, or PROSWIFT. And the National Science Foundation and NASA have supported space-time research programs like Berger and Ridley. For example, Ridley, Krämer, and their collaborators recently received $ 3.1 million in grants from NSF to develop new computer simulations and space software, among other things.
Our dependence on technology in space is accompanied by growing vulnerabilities. Some space scientists speculate that we have not found alien civilizations because some of those civilizations have been destroyed by very active orbiting stars, which could strip a formerly habitable atmosphere of the world and expose life on the surface to harmful stellar radiation and space. time. Our sun is not as dangerous as many other stars that have more frequent and intense magnetic activity, but it has the potential to be dangerous to our way of life.
"Globally, we have to take space time seriously and prepare. We don’t want to wake up one day and all of our infrastructure is down, ”says ESA’s Luntama. With key satellites and power grids suddenly destroyed, we wouldn’t even be able to use our phones to call for help.