Chad Blakley / Lights Over Lapland

Auroral lights glow in the skies over Sweden's Abisko National Park on Jan. 13.

It might sound scary to hear that a giant blob of solar plasma is heading straight for us, but don't panic: Space weather forecasters say this solar outburst should deliver nothing more than a spectacular show up north.

"We're not going to be in for a big disturbance," said Norm Cohen, senior forecaster at the National Oceanic and Atmospheric Administration's Space Weather Prediction Center in Colorado. "The northern tier of the United States might be able to see aurorae."

The outburst of electrically charged plasma — also known as a coronal mass ejection, or CME — blasted out from the sun on Jan. 13, sparking a radio blackout. It's taken several days for the blob itself to travel the 93 million miles between the sun and here, but forecasters now expect it to sweep over Earth's magnetic field early to midday Thursday.

When strong solar storms interact with the magnetosphere, they can spark satellite outages and disrupt electric power grids. Fortunately, this one shouldn't be that strong. (In geekspeak, let's just say that the maximum Kp is expected to reach no higher than 4. NOAA's space weather scale lays out the effects associated with higher Kp levels. Check out the prediction center's Facebook page for space weather updates.)

The most visible effect should be the northern lights generated by the interaction between the electrically charged solar particles and atoms in Earth's upper atmosphere, as explained on the "Causes of Color" website. This week's geomagnetic flare-up should add to what's already been a great week for auroral displays in northern latitudes.

Chad Blakley, a photographer at Sweden's Abisko National Park, sent in the beauty you see above. "It looks like there may be more powerful auroras in the days ahead," Blakley said in an email. "It is a very good time to be an aurora photographer!"

For more of Blakley's beauties, check out the Lights Over Lapland website or the LOL Facebook page.

Glowing reports are coming in from space as well. Here's a picture captured by the Department of Defense's DMSP F-18 OLS low-light imager on Jan. 13. The green outlines show Ireland and Britain down south, and Iceland and Scandinavia up north. The ghostly wisps crossing the frame are the northern lights. It's conceivable that the bright streaks you see in this satellite picture are the same ones visible in Blakley's pictures.

DOD via Mark Conner / SpaceWeather.com

The northern lights show up as ghostly streaks of white in a satellite picture captured on Jan. 13 by a low-light imager on the Defense Department's DMSP F-18 meteorological satellite.

Are there more solar blasts heading our way? SpaceWeather.com notes that a complex sunspot region known as AR1654 is pointing in our direction and has the potential to send more big blobs of plasma our way. But Cohen said the worries about that particular sunspot have been receding.

"It's been fairly quiet in terms of flare production," he said. "If anything, it's beginning to show signs of decay."

In fact, there's been increasing talk that this year's expected peak of the sun's 11-year activity cycle could be relatively wimpy. Cohen said he didn't want to make that sweeping of a prediction — but he did admit that there hasn't been as much disruption as some people might have feared.

"The activity hasn't been all that impressive yet," he said.

More auroral glories:

• Top spots to see the northern lights
• Video: Northern lights captured on camera
• Cosmic Log archive on auroras

Alan Boyle is NBCNews.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. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

Ed Stockard

Atmospheric optics turn sunlight into a celestial display as seen from Summit Station in Greenland on Oct. 14. Ed Stockard, one of the workers at the federally funded research station, says the display includes a halo, sun dogs, an upper tangent arc and more. "My eyelashes froze together, and my cheeks were getting nipped pretty good," Stockard writes.

Is this heaven? No, it's Greenland — lit up by a dazzling display of refracted sunlight.

These pictures are from Ed Stockard, who's part of the team at Summit Station on the peak of the Greenland ice cap. The research facility, which is funded by the National Science Foundation, serves as an observation post for the complex interactions between the atmosphere and one of the world's biggest reservoirs of ice.

The station is also an observation post for sky phenomena ranging from the northern lights to sun halos. And judging by his Flickr photo gallery, Stockard is getting an eyeful this season.

But there's more than meets the eye: Over at the Atmospheric Optics website, Les Cowley points out 11 separate optical phenomena that are on display. The combination of halos, arcs, sun dogs and a sun pillar has earned Stockard's Arctic scene a place as the Optics Picture of the Day.

You don't have to live in the Arctic to see the sun's weird effects. In midnorthern latitudes, this time of year brings misty days, and even some days when ice crystals hang in the air. That's prime time for halos, sun bows and moon bows, fog bows and more. Cowley's website guides you through all the magic that the air can provide — and for still more examples of that magic at work, click on the links below.

Ed Stockard

Buildings at Greenland's Summit Station are silhouetted by the sun and atmospheric effects.

Ed Stockard / Les Cowley / AtOptics.co.uk

A chart from the Atmospheric Optics website catalogs 11 optical effects that can be seen in Ed Stockard's fisheye-camera view of the sun at Summit Station.

More about atmospheric optics:

• Whoa! It's a quadruple rainbow!
• Optical illusions and light shows
• 'Tis the season of sky oddities
• 'Two suns' spotted in China

Alan Boyle is NBCNews.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. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered by email every weekday. You can also check out "The Case for Pluto," my book about the dwarf planet and the search for new worlds.

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.

Brad Goldpaint

Photographer Brad Goldpaint captured this view of the northern lights over Crater Lake, Ore., early Sunday.

A double-burst of solar particles sparked auroral lights over the weekend, as expected — but at least in some parts of the world, the colors were not what you'd expect. Instead of the typical greenish glow, observers reported seeing reds, pinks, violets and even blues.

"It's been many years since I saw the blue in our auroras, but Saturday night they came back," John Welling reported in a note accompanying the photo he posted to SpaceWeather.com.

Pinks, reds and blues also dominated the scene captured on camera early Sunday by Brad Goldpaint, from a vantage point above Oregon's Crater Lake. In an email, Goldpaint told me the opportunity came about "by pure coincidence."

"Capturing this famous light show had been a dream of mine for several years, but I could not have imagined the lights showing up in my own backyard!" Goldpaint wrote. "After setting up near the Rim Village Visitor Center lookout area, I began to notice a faint band of moving light slowly making its way from behind the Watchman Tower, around 1:30 a.m. My camera began picking up bright pink bursts of light towards the north, with what also looked like unfamiliar vertical bands of light stretching upwards from the horizon. I quickly changed my camera’s white balance to confirm I was not picking up some random light pollution, or hallucinating in my drowsy state. Following additional exposures, I came up with the same amazing results. The magical shifting scene continued until sunrise, and like most days in the wilderness, I was awed and humbled by true nature personified."

The photo now graces Brad's portfolio at GoldpaintPhotography.com.

The colors of the aurora depend on the wavelength of the light emitted when fast-moving, electrically charged particles from the sun interact with different types of atoms and ions in Earth's upper atmosphere. If the particles hit mostly oxygen atoms, the light will be in the greenish-yellowish-reddish range. Collisions with nitrogen atoms produce the blue, purple and deep red hues.

The altitude of the auroral glow also affects the color: At altitudes between 60 and 120 miles (100 and 200 kilometers), the oxygen emissions tend toward the green side of the spectrum. At higher altitudes, you'll see more red. Blend all those colors, and you get a beautiful, wide-ranging palette.

The "Causes of Color" website provides a fuller spectrum of information. And speaking of a fuller spectrum, here are more of the weekend's colors, plus a bonus video:

Randy Halverson

Pink and purple rays highlight this picture of the aurora as seen from South Dakota's Black Hills by Randy Halverson. Technical details: Canon 5D Mark III, Canon 24-70, f/2.8 ISO 3200, 20-second exposure. For more of Halverson's images, click on over to Dakotalapse.com.

Stephen Voss

Stephen Voss snapped pictures of the southern lights from a spot near Invercargill in the south of New Zealand. "A dull arc hung around for a couple of hours before suddenly exploding with a mixture of rays and curtains," Voss told SpaceWeather.com. Check out Voss' gallery at Deep South Astrophotography.

Scott Lowther

Scott Lowther snapped this panoramic picture of Saturday night's auroral display as seen from Tremonton, Utah. The shot was taken with a Nikon D5000 and a 55mm lens at f/1.4 with 6-second exposures. For more of Lowther's photos, check out the Art by Earthlings website.

Shawn Malone / LakeSuperiorPhoto.com

Shawn Malone snapped this picture before dawn on Sunday morning from Marquette, Mich. "Got to witness the tail end of aurora activity as the skies cleared about 15-20 minutes before the sunrise light moved in," Malone told SpaceWeather.com. "Photos taken between 3:50 a.m. and 4:15 a.m. Bright aurora, with rays of light overhead, almost forming a corona. Beautiful purples came through on the exposures, but only light visible to the eye, as is typical with auroras right before sunrise." Check out LakeSuperiorPhoto.com for more of Malone's work.

More auroral glories:

• Northern lights blaze again on video
• Farewell to the northern lights
• Northern lights make for must-see TV
• Southern exposure for auroral lights
• Slideshow: The best of the northern lights
• Cosmic Log's auroral archive

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 / LMSAL via SpaceWeather. com

This color-coded image combines observations made by NASA's Solar Dynamics Observatory in several extreme ultraviolet wavelengths, highlighting a bright X-class flare toward the upper left of the sun's disk on March 6.

 The sun unleashed one of the biggest flares ever seen during its current activity cycle late Tuesday — an X5.4-class outburst strong enough to trigger a radio blackout. The resulting geomagnetic storm could affect electrical grids, communication links, satellite navigation systems and airline schedules over the next couple of days.

The outburst at 7:24 p.m. ET was followed about an hour later by an X1.3-class blast. Solar flares are rated on a letter-plus-number scale, with X being the most powerful category. Usually the numbers run from 1 to 9, but X-class flares can run higher. The highest reading recorded recently is an X28, observed in 2003.

Joe Kunches, a space scientist with the National Oceanic and Atmospheric Administration's Space Weather Prediction Center, says the double blast made for a "Super Tuesday," in a different sense from the political meaning.

The big question is, what effect will this solar activity have on Earth? The solar blasts threw off waves of electrically charged particles known as coronal mass ejections, or CMEs. Those waves are now speeding outward, and space-weather forecasters expect them to touch off strong geomagnetic storms when they interact with Earth's magnetic field late Wednesday and early Thursday.

"The most northern states in the 'Lower 48' should have a chance to see the aurora," the prediction center reported on Facebook.

Could something more serious happen? All this activity is already whipping up an S3 solar radiation storm. "Such a storm is mainly a nuisance to satellites, causing occasional reboots of onboard computers and adding noise to imaging systems," SpaceWeather.com's Tony Phillips said.

The coming geomagnetic storm is predicted to reach the G3 level, which could trigger alarms on electrical power systems and create intermittent problems for GPS navigation services. Some airline flights are likely to be rerouted so they don't fly so close to the poles, and problems could arise with communication systems in polar regions. That's the bad news. The good news is that NASA and NOAA have lots of resources in space to monitor solar activity, giving network operators more time to assess and prepare.

Check out NOAA's chart of space weather scales to learn more about what S3, G3 and the other storm desigations mean.

Experts at the Space Weather Prediction Center say the storm generated by the X5.4-class flare is on a trajectory to deliver a glancing blow rather than a direct hit on Earth, but they caution that the sunspot region responsible for the flare, AR1429, "remains potent, and subsequent activity is certainly possible."

For now, chances are that the most noticeable effect for most people will be an upswing in the number of fantastic pictures of the northern lights. AR1429 has been acting up over the past few days, and SpaceWeather.com has been adding plenty of stunners to its aurora gallery. If you get a nice snapshot, please consider sharing it with us via the Cosmic Log Facebook page or msnbc.com's FirstPerson in-box.

Update for 4:40 p.m. ET March 7: NASA's Goddard Space Flight Center reports that the coronal mass ejections sent out on Tuesday are projected to impact Earth and Mars as well as several interplanetary spacecraft, including NASA's Spitzer Space Telescope, the Messenger probe at Mercury and the sun-watching STEREO-B satellite. The NASA advisory also notes that the X5.4-class flare was the strongest solar outburst since an X6.9 blast on Aug. 9, 2011. In that previous case, the resulting CME was not directed at Earth, and no ill effects were felt.

Update for 5 p.m. ET March 7: A lot of commenters are talking about the Carrington Event of 1859, a solar storm that was so strong it frazzled telegraph wires. That was associated with what was surely an off-the-scale solar flare, much more powerful than the X28 referenced at the beginning of this item — so I've rephrased that reference accordingly.

More about solar storms and auroras:

• Northern lights shine through a crack
• Rocket flies into the northern lights
• Aurora extravaganza glows in space
• Planet looks back at the northern lights
• Slideshow: The best of the northern lights
• Cosmic Log's auroral archive

This item was first published at 12:30 a.m. ET March 7.

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.