The sun sent out a flare powerful enough to disrupt radio communications over Europe today, along with an eruption of electrically charged particles that just might sweep past Earth's magnetic field in time to spark a Fourth of July show of auroral fireworks.

The M5.6-class solar flare, observed by NASA's Solar Dynamic Observatory at 6:52 a.m. ET (10:52 GMT), was almost powerful enough to cross over from the medium M-class category to an extreme X-class event, SpaceWeather.com's Tony Phillips noted. "A pulse of X-rays and UV radiation from the flare illuminated Earth's upper atmosphere, producing waves of ionization over Europe," he wrote.

Such waves can spark bursts of radio static, as recorded by Rob Stammes in Norway and noted by the National Weather Service's Space Weather Prediction Center. "Radio blackout storms have been observed in the past 24 hours," the center reported on its Facebook page.

SpaceWeather.com says the solar eruption threw out a coronal mass ejection, or CME — not directly toward Earth, but in a southerly celestial direction. In the video above, you can see the solar material blurping downward and outward from a monster sunspot region known as AR 1515.

Phillips writes that the "south-traveling cloud could deliver a glancing blow to our planet's magnetosphere on July 4th or 5th." However, the Space Weather Prediction Center says the CME "is not expected to disturb the field during the forecast period."

The sun is in the midst of an upswing in its 11-year activity cycle, heading toward an expected maximum in 2013. Right now there are five sunspot regions on the sun's Earth-facing side, and two of them — 1513 and 1515 — are considered capable of sending out M-class flares. Such flares are generally associated with moderate disruption of radio communication and navigation systems. As for today's CME, the most likely effect will be heightened displays of the northern and southern lights.

CME or not, it looks as if it's a good week for auroras, judging from the pictures being sent in to SpaceWeather.com's real-time image gallery. The prime time for auroras generally begins at just about the time of night that the fireworks shows are finishing up. And there's more to see besides the fireworks: This happens to be a great week for seeing the full moon and Mars in sunset skies, or seeing Jupiter and Venus just before dawn. Sky and Telescope has the week's rundown.

So if you're out and about on the night of the Fourth, sit back and enjoy the fireworks — whether they're terrestrial or celestial in origin. And if you happen to snap a great picture of the northern or southern lights, please share it with us via our FirstPerson photo upload page. If we get some good ones, we'll pass 'em along after the Fourth.

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

NASA / SDO

An "intensitygram" from the Helioseismic and Magnetic Imager on NASA's Solar Dynamics Observatory shows the double-barreled sunspot active region 1416 pointing toward Earth.

As solar activity builds toward an expected peak in 2013, a double-barreled sunspot has been doubling in size over the past couple of days and now has the potential to shoot significant eruptions in our direction.

It's not certain that active region 1416 will erupt with coronal mass ejections as violent as the blasts that were thrown off by the sun late last month. But it has developed a mixed "beta-gamma" magnetic field that packs enough energy to throw off medium-scale solar flares, SpaceWeather.com reports.

"Any such eruptions this weekend would be Earth-directed as the sunspot turns to face our planet," SpaceWeather's Tony Phillips wrote.

Medium-size M-class flares are generally associated with the kinds of solar storms that produce enhanced auroral lights, but not huge inconveniences on Earth. It's the X-class flares you really have to watch out for: That level of solar storming could affect radio communications as well as satellites and electrical grids if the operators of those systems aren't careful.

NASA and the National Oceanic and Atmospheric Administration have a wide array of space assets monitoring the sun, and for now all's quiet on the solar front. NOAA's Space Weather Prediction Center reported some problems tracking the Advanced Composition Explorer, a satellite that plays a key role in tracking solar storms, but those problems are expected to go away as ACE's orientation with respect to the sun improves.

NASA / ESA / SOHO / NOAA

The heart-shaped coronal mass ejection can be seen at about the 10 o'clock position on this image from the Solar and Heliospheric Observatory.

The prediction center's Facebook page reports that on Friday, the sun threw off a slow-moving coronal mass ejection, or CME — in the shape of a heart, no less. "A preliminary model run predicts this CME will arrive, appropriately enough, on Valentine's Day," NOAA reports. So if you're out with your Valentine that night, particularly in Scandinavia or Canada, watch the skies. Even if the earth doesn't move, the aurora might glow.

Meanwhile, the sunspot region that caused all the auroral fireworks last month, known as AR1402, has moved around the far side of the sun. Solar scientists will be interested to see how that region has changed when it comes back into view. We're still a year out from the anticipated peak in the sun's 11-year activity cycle, so there'll be lots of sun-watching ahead. The best ways to keep track on a daily basis is to check in with NOAA's space weather center and SpaceWeather.com.

In the meantime, catch up on your oohing and ahhing over the northern lights by clicking on these links:

• Auroral extravaganza glows in space
• Planet looks back at northern lights
• Auroras spark awe across the north
• Northern lights go way, way south
• Speed through Lapland's lights
• Beautiful blasts from solar storms
• Get a video view of Canada's aurora
• Slideshow: The best of the northern lights
• Cosmic Log's auroral archive

Update for 4:45 p.m. ET Feb. 11: Speak of the devil ... SolarHam.com reports that AR1402 has indeed made its reappearance on the edge of the sun's disk and was observed firing off C-class solar flares.

Update for 2:30 p.m. ET Feb. 12: The double-barreled active region is moving off its direct-fire orientation as the sun continues to rotate, and although the sunspots have continued to grow, it's becoming less likely that any CME from that region would score a direct hit on Earth and its magnetic field. So for now, the most significant effect we can look forward to is a round of colorful northern lights around Valentine's Day.  

Tip o' the log to Jason Major at Universe Today.

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding Cosmic Log's Google+ page to your circle. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for other worlds.