A massive storm rolling in from space this summer knocked out several Global Positioning System satellites, rendering them temporarily useless until they could reboot. The violent weather, in June, had only minor repercussions; however, the fact remains that for a brief period of time our global navigation satellite system failed.
Space storms are a growing concern among scientists who see cracks in the critical infrastructure on Earth—the power grid, GPS navigation and sensitive communication satellites.
“We know that solar storms are real and that they are a threat,” says Roger Dube, professor in the Chester F. Carlson Center for Imaging Science at Rochester Institute of Technology. “The question is, how big a threat and when is it going to be really bad? What do we need to do to protect ourselves?”
“My original project was oriented toward the colonization of Mars,” Dube says. “In order to understand what will happen at Mars, we’ve had to step back and look at the impact of these storms on Earth. We’ve come to realize that there is a big problem even here in terms of our potential sensitivity to a storm like this now that our society has become so technologically dependent. I think our overall level of awareness and concern has increased because we’re seeing more data that says this is not that rare an event.
“If we can understand what happens on the sun to cause space weather storms on Earth, then the only thing we have to change is to look at the direction of the storm as it goes into space. If it’s going to hit Mars then we know that our prediction can be applied to that planet.”
Dube has switched his research priorities to address growing concerns about Earth’s vulnerabilities. His work developing an early storm warning system for future Mars colonists has assumed “local” importance.
During a space weather storm, the solar version of hurricane-force gusts flow through the interplanetary region carrying X-rays and high-energy particles emitted from solar flares and coronal mass ejections—high-energy explosions on the sun—the source of the storm in June.
No one knows for sure what causes space storms, Dube notes. In rare events, comets collide with the sun and explosions result; mostly, however, the turmoil underneath the surface of the sun produces the eruptions.
“There are a lot of complex forces that are acting on the sun. It has magnetic fields, electric fields and extremely high temperatures. It has high densities of charged elementary particles. All of these things contribute in a complex way to the dynamics of what’s happening underneath the solar surface, and all of a sudden you get this explosion.”
Unlike Mars’ weak defenses, Earth’s strong, protective magnetic field and atmosphere withstand the majority of storms. Massive assaults of X-rays and high-energy particles on today’s technological systems present scientists with unknown scenarios.
“When a significant wave of particles comes, it can be so intense that it actually bends the Earth’s magnetic field way beyond where it naturally belongs to a point where the magnetic field lines nearly cross,” Dube says. “When they bend that much, everything snaps and you get this huge deposit of charge at the poles.”
The burst of charged particles enters the Earth’s atmosphere and creates ribbons of light known as the aurora borealis. The same high-energy particles responsible for the colorful display can sizzle satellites, expose airplane passengers to radiation and cripple the power grid in a surge of current.
“When these storms come along, they induce extra current into the power grid that causes the power to ride up over the top of its designed operating point, much like a wave passing,” Dube says. “Circuit breakers shut it down, or if they don’t respond fast enough, parts of the grid can melt. We’ve had several documented cases where solar storms like this have caused transformers to melt and power lines to go down.”
The Space Radiation Analysis Group at Johnson Space Center in Houston, in conjunction with the National Oceanic and Atmospheric Administration, regularly issues alerts to power suppliers and commercial airline carriers within 30 to 60 minutes of a storm. Dube thinks a better monitoring system could provide three to five days advanced warning.
“There are people that are saying that if a big solar storm hit it could take us three to five years to get our power back,” Dube says. “No power for three to five years? You’d have no food that could be refrigerated. There would be no way to transport oil from the Middle East to the United States. Imagine how hard it would be to contact a distant factory to get replacement parts. It would be a major reset to humanity.
“Those are doomsday scenarios, but at least they’ve gotten people’s attention,” Dube says. “We should at least try to find a way to predict as reliably as possible what might happen with this.”
Dube and his group of seven students have made significant advances in the ability to predict space weather storms affecting Earth. Their research agenda has expanded to include a variety of solar physics and stellar physics objectives:
• Recognizing features on the sun for use in a predictive process
• Studying different aspects of coronal mass ejections
• Linking activity on the sun (such as sunspots) with other types of impacts on Earth (such as the aurora borealis and radio storms)
• Studying solar-wind drag on coronal mass ejections
• Tracking the movement of spots on stars to determine rotational speed
The essence of Dube’s research lies in complex pattern recognition problems. The neural network his team developed digests the massive amount of data taken from different types of variables, such as electricity and magnetism. Another variable includes the concentrations of nitrates from the upper atmosphere that have settled in ice cores taken at the North Pole.
“What’s happening is that we’re able to recognize these precursors in this data that’s within half a day of the event. That’s good, but we’d really like to have it several days in advance so that you could do something about it,” Dube says. “For example, with enough warning we can turn our satellites away from the sun so they don’t get hurt by the particles that hit them as the storm passes.”