The storm, originating from a massive solar flare Tuesday -- the third most powerful solar eruption ever observed -- hurled electronically charged gas at a speed of 2,000 kilometers (1,250 miles) a second straight towards the Earth.

It hit the Earth just after 1600 GMT Wednesday, several hours earlier than scientists had expected, according to the forecasters at the US National Oceanic and Atmospheric Administration's Space Environment Center.

NOAA reports "indicate that power grids in the northern United States and Canada are feeling the effects of the extreme geomagnetic storm," the agency said in a statement. "Utilities are experiencing power surges and are closely monitoring their systems.

NOAA space weather officials classified the geomagnetic storm as a G-5 or "extreme" on a scale that runs 1 to 5. In terms of frequency, this level of storm occurs only once, if at all, during the 11-year solar cycle of activity, officials said.

"It took the geomagnetic storm just 19 hours to reach Earth after it occurred on the sun," said NOAA space weather forecaster Larry Combs. "That's one of the fastest traveling solar storms this (25-year) cycle."

The solar flare also caused an S-4 radiation event, the fourth largest in history since NOAA began keeping records in 1976 and the second largest radiation event during this solar cycle.

NOAA reported that aurora borealis -- northern lights caused by the charged particles from the Sun -- have been seen in the United States as far south as El Paso, Texas.

NOAA officials believe the geomagnetic storm will continue to affect the Earth over the next two weeks.

The eruption sent rays-X travelling at the speed of the light towards Earth, causing a geomagnetic storm at a height that ranged from 50 kilometers (31 miles) to a few hundred kilometers (miles) above the Earth's surface.

The X-rays interfered with radio transmissions in certain frequency bands, in particular those used for the communication by airplanes travelling at a high altitude close to the Earth's poles.

Specialists fear the solar storm could damage some communications satellites, and possibly land-based power grids.

Due to the high level of radiation emanating from the solar storm, the two crew members of the International Space Station have been ordered as a precaution to spend periods of time sheltered in the Zvezda service module, which offers them higher protection from increased radiation levels.

The Sun storm headed toward the Earth five times faster than previous emissions, said Bernhard Fleck, a scientist in charge of a US-EU space observation satellite.

The Sun's most powerful explosion of flares and gases into space in the current cycle occurred in April 2000, but that burst was directed away from the Earth.

Tuesday's eruption, which was filmed, came from the central part of the sun that faces the earth.

Magnetic storms do not present a danger to personal health because the ionized particles are absorbed or bounced off by the Earth's thick atmosphere.

SPACE.WIRE