Mainers had front row seats for yet another spectacular celestial display, when G5 strength solar eruptions (on a scale from 1 to 5) produced the strongest geomagnetic storm in 20 years. Storms of this size can cause disruptions impacting satellite transmissions, communication networks and power grids.

The resulting Aurora Borealis, (Northern Lights) display was caused when at least six gigantic solar flares, called Coronal Mass Ejections (CME’s), erupted from a sunspot that is 17 times the diameter of Earth. The National Oceanic Atmospheric Administration described a CME as a billion tons of plasma ejected from the sun traveling at speeds of millions of miles per hour.

When the solar particles reach Earth, they travel along its magnetic field lines, which are centered in an oval ring around Earth’s magnetic poles. The solar particles excite nitrogen and oxygen molecules in our atmosphere, which then release photons of light in different shades of red, purple and green.

When a CME reaches Earth, it can produce some of the biggest geomagnetic storms and thus, some of the brightest and most active auroras which extend closer to the equator than usual. This recent Aurora spectacle was of such magnitude, that along with clear skies, it was seen as far south as Florida and Texas, all across the country.