WASHINGTON – NASA is warning a new sunspot spewing powerful X-class flares is beginning to rotate to a position directly in line with Earth.

A direct hit on Earth from an X-class flare could cause major disruptions – or even destruction – to the U.S. electrical grid, which already is very vulnerable, as well as to life-sustaining critical infrastructures dependent on the grid to function.

NASA said the warning regarding the sunspot, AR 2151, could last for weeks.

Eruptions that drew the attention of space experts began last Sunday with an M5.6 solar eruption, which is one tenth the strength of an X-class flare.

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X-class flares are the most power solar flare. The least intense flare is a C-class. M-class flares ranked as mid-range.

"Solar flares are powerful bursts of radiation," explained NASA spokeswoman Karen Fox. "Harmful radiation from a flare cannot pass through Earth's atmosphere to physically affect humans on the ground. However, when intense enough, they can disturb the atmosphere in the layer where GPS and communications signals travel."

Some of the flares spewing from the sun's surface can be at least 14 times the size of Earth.

NASA and the National Science Foundation has estimated that if the U.S. sustained a direct hit from an X-class flare, it would cost the nation upward of $2 trillion in the first year and kill up to 90 percent of the U.S. population due to the lack of services, starvation and disease.

The Defense Department is preparing to harden its systems to defend against an EMP event, whether from a solar flare or nuclear attack. But EMP experts point out DOD relies on the civilian electrical grid, which will remain vulnerable unless action is taken.

The flares from AR 2151 were first detected Sunday by NASA's powerful Solar Dynamics Observatory and Solar Helospheric Observatory, or SOHO, a joint NASA and European Space Agency activity.

The sun is going through an 11-year cycle, which at its peak is called a solar storm maximum. The current cycle is known as Solar Cycle 24.

Even as the intensity of flares from the sun begins to diminish, they could hit Earth well into subsequent years, until the cycle reaches a so-called solar-storm minimum. Then, a new cycle will begin some five-and-a-half years out.

Not ready for prime time?

In response to defense-system vulnerabilities to an electromagnetic pulse, or EMP, strike, the Defense Department has decided to harden all its "ground-, air-, maritime, and space-based platforms, electronic and electrical systems, subsystems and equipment."

Rather than after-the-fact remedial measures, the DOD directive said such measures will take place at the time of acquisition of military systems and equipment that incorporate electronics.

The directive states DOD will "interface with federal agencies and other organizations as required to promote cooperation and information exchange." That means DOD will need to work with the U.S. Department of Homeland Security, which deals directly with national emergencies and has a say on protecting the national grid.

However, DHS presently does not include an EMP event as one of 15 emergency National Planning Scenarios, which include responses to floods, hurricanes and terrorist attacks.

Until now, DOD has left it to DHS to deal with protection of the electrical grid from an EMP event.

Yet, DOD facilities rely 99 percent on the vulnerable civilian electrical grid to function. While it own platforms and equipment may be hardened against an EMP event up to an E3 level, characterized by a very slow pulse, the bases could become defenseless, depending on backup generators.

EMP experts point out to WND that President Obama can sign an executive order requiring DHS to include EMP as one of its national planning scenarios.

Because DOD facilities rely on the civilian electrical grid to function, unless it similarly is hardened, U.S. defense systems could be seriously affected.

EMP experts add that while DOD's initial undertaking is a good start, such hardening won't protect defense platforms and equipment from a high-altitude nuclear detonation.