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.
The solar storm could cause communication problems, affecting radio and satellite systems. NBC's Tom Costello reports.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
Here is some information on the last few really big storms at:
March 13, 1989 - The Quebec Blackout Storm - Astronomers were busily tracking "Active Region 5395" on the Sun when suddenly it disgorged a massive cloud of superheated gas on March 10, 1989. Three days later, and seemingly unrelated to the solar paroxicism, people around the world saw a spectacular Northern Lights display. Most newspapers that reported this event considered the spectacular aurora to be the most newsworthy aspect of the storm. Seen as far south as Florida and Cuba, the vast majority of people in the Northern Hemisphere had never seen such a spectacle in recent memory. At 2:45 AM on March 13, electrical ground currents created by the magnetic storm found their way into the power grid of the Hydro-Quebec Power Authority. Giant capacitors tried to regulate these currents but failed within a few seconds as automatic protective systems took them off-line one by one. Suddenly, the entire 9,500 megawatt output from Hydro-Quebec's La Grande Hydroelectric Complex found itself without proper regulation. Power swings tripped the supply lines from the 2000 megawatt Churchill Falls generation complex, and 18 seconds later, the entire Quebec power grid collapsed. Six million people were affected as they woke to find no electricity to see them through a cold Quebec wintry night. People were trapped in darkened office buildings and elevators, stumbling around to find their way out. Traffic lights stopped working, Engineers from the major North American power companies were worried too. Some would later conclude that this could easily have been a $6 billion catastrophe affecting most US East Coast cities. All that prevented the cascade from affecting the United States were a few dozen capacitors on the Allegheny Network. [Newspaper Archive]
June 6, 1991 - Severe sun storm threatens utilities [New York Times, June 6, 1991, p. A16].
July 15, 2001 - The Bastille Day Storm - Solar flare threatens the earth with storm [New York Times, July 16, 2001 p. 21]. Minor damage reported from geomagnetic storm [New York Times, July 17, 2001 p. A17]
October 29, 2003 - The Halloween Storm - This Halloween Storm spawned auroras that were seen over most of North America. Extensive satellite problems were reported, including the loss of the $450 million Midori-2 research satellite. Highly publicized in the news media. A huge solar storm has impacted the Earth, just over 19 hours after leaving the sun. This is one of the fastest solar storm in historic times, only beaten by the perfect solar storm in 1859 which spent an estimated 17 hours in transit. A few days later on November 4, 2003 one of the most powerful x-ray flares ever detected, swamped the sensors of dozens of satellites, causing satellite operations anomalies….but no aurora. Originally classified as an X28 flare, it was upgrade to X34 a month later. In all of its fury, it never became a white light flare such as the one observed by Carrington in 1859. Astronauts hid deep within the body of the International Space Station, but still reported radiation effects and ocular 'shooting stars'.