As the 'X-class' flare - the most powerful of its kind - bombarded our planet's magnetic field for most of the day, it was feared the activity could disrupt power grids, satellite navigation and aeroplane routes.
However, no major incidents have so far been reported - but that could still change.
The solar storm - ten times stronger than a normal 'solar wind' - is likely to last through Friday morning, and the region that erupted could still send more blasts our way.
At the height of the flare activity Joe Kunches, a scientist for the National Oceanic and Atmospheric Administration, said: 'It's hitting us right in the nose' - calling it the sun's version of 'Super Tuesday'.
But he later said his space weather prediction agency might have overestimated the effects of the bombardment.
The sun's activity on March 8, 2012. A strong geomagnetic storm is racing from the sun towards Earth
Heading our way! A Nasa handout photo shows the massive solar flare that could affect power grids, GPS and plane flights - although no incidents have so far been reported
The X1 solar flare in a new active region on the sun, region 1429. It has let loose two M-class flares and one X-class so far. Material erupted from the sun with each flare, though due to the fact that this active region is still off to the side of the sun, they will likely have a weak effect on Earth's magnetosphere
'We expected the freight train. The freight train has gone by, is still going by, and now we're watching to see how this all shakes out,' he told Fox News.
He added: 'We estimated the speed but we missed the spin on the ball.' Others had similar hunches to Kunches. Nasa solar physicist Alex Young reckoned the flare 'could give us a bit of a jolt'.
However experts have warned solar storms can be devastating, and the flare may just be a preview ahead of a peak in the sun's activity next year.
Restless: The sun is in a period of intense activity that will peak next year. This Nasa picture was taken today
Hot stuff: An image acquired by the Solar Dynamics Observatory today that captures the sunspots with amazing clarity
Solar storms have three ways they can disrupt technology on Earth: with magnetic, radio and radiation emissions.
Kunches said power companies around the Earth had been alerted for possible outages.
The timing and speed of a storm determines whether it will knock off power grids, he said.
Solar storms can also make global positioning systems less accurate, which is mostly a problem for precision drilling and other technologies. There also could be GPS outages.
The storm also can cause communication problems and added radiation around the north and south poles, which will probably force airlines to reroute flights. Some already have done so.
Satellites could be affected by the storm, too. Nasa spokesman Rob Navias said the space agency isn't taking any extra precautions to protect astronauts on the International Space Station from added radiation from the solar storm.
Space-watchers said the impact - which is mainly felt in the polar regions - could be strong enough to allow a glimpse of the famous northern lights in Britain overnight.
Solar storms are a natural phenomenon which occur as a result of the natural rises and falls in the sun's magnetic activity over an 11-year cycle which will peak in 2013-14.
When it releases magnetic energy, bursts of charged particles -- known as coronal mass ejections, or CMEs - can be flung towards Earth and interfere with our magnetic field.
The sun-spot group 1429 is seen on the surface of the sun on this photo taken from Salgotarjan, 109 km northeast of Budapest, Hungary
The explosions on the sun created a 'coronal mass ejection' which sent a large amount of charged particles into space, but they are expected to avoid Earth because the sun spots are off to the side of our star
After a large solar flare in August, this is the biggest since 2007, according to the US space agency Nasa.
Dr Craig Underwood, Deputy Director of the Space Centre at Surrey said: 'The event is the largest for several years, but it is not in the most severe class.
'We may expect more storms of this kind and perhaps much more severe ones in the next year or so as we approach solar maximum.
'Such events act as a wake-up call as to how our modern western lifestyles are utterly dependent on space technology and national power grid infrastructure.'
The Met Office warned businesses about the storm on Wednesday after two smaller solar flares earlier this week.
This flare was categorized as an X5.4, making it the second largest flare -- after an X6.9 on August 9, 2011 -- since the sun's activity segued into a period of relatively low activity called solar minimum in early 2007
This extreme ultraviolet wavelength image provided by NASA provides another look at a solar flare, which could also force airlines to reroute
This colour-coded image combines observations made by Nasa in several extreme ultraviolet wavelengths, highlighting a bright X-class flare toward the upper left on March 6
Scientists are working hard to understand the physics of these events so they will be able to predict them with more accuracy.
Professor Alan Woodward, Department of Computing, University of Surrey said solar storms could cause devastation by knocking out computer systems, medical devices, aircraft and mobile phones.
He said: 'We have the potential this year to see what planners call a "Black Swan" event: one that is unlikely but if it happens will have an extraordinary impact on our lives.'
In 1972, a geomagnetic storm provoked by a solar flare knocked out long-distance telephone communication across the US state of Illinois.
A disturbance in 1989 plunged six million people into darkness across the Canadian province of Quebec.
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