A massive solar flare that erupted on the Sun over the weekend have crossed the solar system and hit the Earth's magnetic field at approximately 8:15 a.m. EDT (12:15 UT) on Sept. 26, according to NASA.

The flares, which are backed by a small radiation storm and a spectacular coronal mass ejection (CME), has kicked off moderate (G2) geomagnetic storms for low latitudes, but high latitudes are seeing severe (G4) levels of activity, according to the U.S. National Oceanic and Atmospheric Administration (NOAA).

Skywatchers in northern Europe are already seeing some aurora activity and it may persist long enough for viewers in North America.

The sun has unleashed a series of solar flares over the last weekend. All the flares erupted from the same sunspot, No. 1302. It started on Saturday morning when an X1.9-category flare erupted at 5:40 a.m. EDT.

The active region has unleashed M8.6 and M7.4 flares on Sept. 24 and an M8.8 flare early on Sept. 25. But the good news is none of them have been squarely Earth-directed, but this could change as the sunspot turns toward our planet in the days ahead.

The flares are classified according to how powerful they are, as A, B, C, M or X, with X being the most powerful.

The flares are seen first, as the light and radiation take only eight minutes to get to Earth. The CME moves slower and takes days, in the same way that thunder follows lightning.

Solar activity waxes and wanes over an 11-year sun weather cycle. With the sun transitioning to a busier cycle in 2013, scientists expect more solar activity over the next three to five years.

The largest recent solar flare was in December 2006, which measured X9 on the solar flare scale.

A solar flare is caused when intense burst of radiation comes from the release of magnetic energy associated with sunspots. Flares are the solar system's largest explosive events. A CME happens when the outer solar magnetic fields are closed, often above sunspot groups, and the confined solar atmosphere can suddenly and violently release bubbles of gas and magnetic fields.

While a strong solar flare increases the chance of a spectacular light show, the electromagnetic pulse can also disrupt satellite communications, power grids and radio traffic when it passes the Earth. Some industries that are usually affected by solar flares include electrical power grid companies, airlines, GPS, military and ocean shipping routes.

The strongest solar storm on record is called the “Carrington Event,” named after Richard Carrington, who viewed and reported on the solar flare in late August and early September,1859. From Aug. 28 through Sept. 4, aurorae of unusual brilliance were observed throughout the globe.

NASA NASA Storm Solar