LOGAN -- Solar flares nearly 93 million miles away have sparked both awe and concerns this week on our small blue-green planet.
People intrigued by space and beauty have enjoyed photographic images of the flaring sun, and of aurora borealis effects the flare caused on Earth.
But airlines, including Delta and United, have rerouted flights that usually travel over the Arctic because of potential communications failures caused by flares.
Ludger Scherliess, who teaches physics at Utah State University, said it's safe to sit back and enjoy photos and footage. Solar flares of this size pose no threat to people on Earth and barely threaten technology.
"This was a fairly large one, an M-9, almost an X, which is the largest class of solar flares," Scherliess said. "A large X would have significant effects on Earth, but they aren't common."
Solar flares are large explosions from the surface of the sun. X-rays and ultra-violet radiation emitted by solar flares can affect Earth's ionosphere and disrupt long-range radio communications.
A 1989 X-class flare destroyed transformers and caused a power outage in Canada's Quebec province.
According to NASA, X-class flares can trigger planet-wide radio blackouts and long-lasting radiation storms.
M-class flares are medium-sized, can cause brief radio blackouts that affect Earth's polar regions and cause minor radiation storms.
C-class flares are small, with few noticeable consequences on Earth.
Scherliess said an 1859 solar flare is both the largest and the first recorded by scientists.
"They reported it was almost as bright as the sun itself," Scherliess said. "They don't last long. A few minutes and it was gone."
If that same flare occurred in modern times, it would cause major technological damage to power grids on Earth and to satellites in space.
"I've seen some estimates that if something like that (1859 flare) would happen again, it would cause $30 billion to $70 billion in damage, because it would have a large effect on our entire fleet of 900-plus satellites," Scherliess said.
We surface dwellers are protected by the atmosphere, he said. Airplane crews over the poles are less protected, because they are higher in the atmosphere, he said. Satellites are unprotected, and astronauts beyond our atmosphere are vulnerable.
NASA scientists routinely monitor space weather conditions to protect astronauts and hardware in orbit from harmful radiation, according to the agency's website.
Scherliess said the solar flares usually occur in cycles, which average about 11 years in length.
"We are just coming out of a very long minimum phase -- much longer than anticipated -- of 14 years," he said. "The last five or six years, we didn't have any flares like this, only very small ones. During solar maximum, where we are headed at the end of 2013, it may happen once or twice a year."
The biggest flares tend to come during phase transitions, Scherliess said.
"The sun goes from a very quiet sun to a very disturbed sun," he said. "It has to do with the build up of the magnetic field. People like to compare it to a rubber band that is stretched more, more, more, and at some point it will snap and release its energy. During solar minimum, we simply don't have these strong magnetic fields."
Scherliess said this week's M-class flare did provide a beautiful show for people who found themselves in the right locations.
"In 2001 and 2003, auroras could be seen in Utah," he said. "With the solar maximum approaching, hopefully we will see it over Utah again."