The sun unleashed its most powerful solar flare in four years Tuesday -- an eruption that could have had serious consequences on Earth if it had taken place on the side of the sun facing the planet.

"We lucked out because the site of the eruption at the sun was not facing the Earth, so we will probably feel no ill effects," Joe Kunches, a space scientist with the National Oceanic and Atmospheric Administration's Space Weather Prediction Center, told MSNBC.

So far, it appears that any consequence felt on the Earth will not cause human injury. A minor proton storm currently on the Earth's surface could affect satellites in high-altitude orbits, and radiation briefly disrupted radio communication at certain frequencies, according to SpaceWeather.com.

Tuesday morning's solar flare -- classified as an X6.9 -- took place at 3:48 a.m. EDT. X is strongest of three classifications of solar eruptions, and was three times larger than the previous largest solar flare in the sun's current cycle, which began in 2008 and should end in 2020. The year expected to be heaviest for solar activity is ahead of us, in 2013.

An MSNBC report explained the science behind the phenomenon: "Solar flares occur when magnetic field lines on the sun get tangled up into knots, building potential energy until they reach a tipping point. Then, that energy is converted into heat, light and the motion of charged particles."

The biggest solar storm on record took place in 1859. The impact of the flare from the Carrington Event (named for the British astronomer Richard Carrington, who discovered the link between sun activity and disturbances on the Earth) were so strong that "people in the northeastern U.S. could read newspaper print just from the light of the aurora," Daniel Baker, of the University of Colorado's Laboratory for Atmospheric and Space Physics, reportedly said at a geophysics meeting in 2010.

According to a National Geographic report, an event of similar scale today could cause devastating damage. "What's at stake are the advanced technologies that underlie virtually every aspect of our lives," the Space Weather Prediction Center's Tom Bogdan told National Geographic.

"We live in a cyber cocoon enveloping the Earth," Baker said. "Imagine what the consequences might be."

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