NASA's Solar Dynamics Observatory captures views of today's M5.6-class solar flare in multiple ultraviolet wavelengths.
By Alan Boyle
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.