OLSTICE AURORA WATCH: On June 18th, sunspot AR2371 unleashed the strongest solar flare in nearly 2 months. The M3-class explosion caused a brief shortwave radio blackout over North America, and it hurled a CME into space. SOHO (the Solar and Heliospheric Observatory) recorded a movie of the expanding cloud:
The CME is not heading directly for Earth. Nevertheless, it is probably geoeffective. According to NOAA computer models, the CME should deliver a glancing blow to our planet’s magnetic field during the late hours of June 21st. High-latitude sky watchers should be alert for solstice auroras.
CME TARGETS EARTH, AFTER ALL: On Nov. 7th, when an X-flare from AR2205 hurled a CME into space, at first it appeared that the cloud would miss Earth. Follow-up computer modeling by NOAA analysts suggests that the CME might deliver a glancing blow to our planet’s magnetic field after all. A complete forecast follows this movie of the eruption recorded by the Solar and Heliospheric Observatory:
The CME left the sun traveling approximately 600 km/s (1.3 million mph) albeit not directly along the sun-Earth line. If the computer models are correct, the outskirts of the cloud should reach Earth mid-day on Nov. 10th (Universal Time). First contact could spark a G2-class geomagnetic storm on Nov. 10th subsiding to G1-class on Nov. 11th. NOAA forecasters are citing storm probabilities as high as 75%.
These storms in the forecast are mild, not extreme, so there is no danger of power outages or communications blackouts. However, the CME impact could spark some beautiful auroras around the Arctic Circle. The lights might even spill across the Canadian border into northern-tier US states such as Maine, Michigan, Minnesota and the Dakotas.
CME IMPACT: An interplanetary shock wave (probably the leading edge of a CME) hit Earth’s magnetic field on Nov. 12th at approximately 2300 UT, filling skies over northern Scandinavia with bright auroras. Oskar Pettersson sends this picture from Luleå, Sweden:
“Half of the sky was green and I stayed out for 5 hours observing the dancing light befor heading home,” says Pettersson.
BROKEN RECORD? The recent sustained activity of sunspot AR1429 has kept the Arctic Circle alight with auroras for almost two weeks. “I have spent many thousands of hours watching and photographing the Northern Lights,” says aurora tour guide Chad Blakely of Abisko Sweden, “and I can honestly say that I have never seen the auroras this strong for so many days in a row.” In a movie he made last night, March 12th, a green tornado of light swirls across Venus and Jupiter:
“We were all absolutely stunned by the natural beauty of this display,” says Blakeley. “I know I sound like a broken record, but sunspot 1429 just will not stop!”
The northern lights take on a weird, rippling shape in a super-wide-angle view captured Sunday night by the Canadian Space Agency’s AuroraMAX webcam in Yellowknife, capital of the Northwest Territories. There’s more from AuroraMAX at the project’s website and on Twitpic.
By Alan Boyle
Is it “auroras” or “aurorae”? The dictionary prefers the former, but either way, there was a multiplicity of auroral awesomeness this weekend — thanks to a solar storm that swept past Earth’s magnetic field over the weekend. During the past few days, we’ve shown off a few stunning images from Norway and Canada, and there’s a new crop to share today.
First, a little explanation for what you’re looking at:
Auroral lights arise when electrically charged particles from the sun interact with atoms and ions high up in Earth’s atmosphere, 60 to 200 miles up. The interaction sets off emissions in wavelengths ranging from blue, to green (the most common color), to red. The colors depend on the energy of the particles in question. To get the full story on that, check out the explanations from the“Causes of Color” website and the University of Alaska at Fairbanks.
This weekend’s auroras were particularly bright because ofa strong solar outburst that occurred on Thursday. There’s an interval between the outburst and the displays because the particles that are ejected from the sun travel at far less than the speed of light. But they’re still pretty speedy — the velocity is on the order of a million miles an hour.
Solar outbursts, known more formally as coronal mass ejections or CMEs, have the potential to disrupt electrical grids or satellite communications. There could be radiation effects on astronauts in orbit or passengers on high-altitude, pole-traversing airplane flights. Thursday’s outburst dealt Earth’s magnetic field a glancing blow, and no significant negative impact has been reported. However, an even stronger CME is currently on its way toward Earth and may force the rerouting of polar flights. Once again, electric-grid managers and satellite operators will be on alert, as will aurora-watchers.
Observers in northern latitudes can look forward to enhanced auroras over the next couple of nights — and the rest of us can look forward to more images like these:
Bjorn Jorgensen’s view of the aurora was captured on Sunday at Grotfjord, close to Tromso in north Norway. “This was amazing,” he told SpaceWeather.com. “It was a wonderful experience to see these stunning auroras.” The bird-of-prey picture was taken with a Nikon D3S camera equipped with a Nikkor 14-24mm lens. Exposure for the pictures in Jorgenson’s set was ISO 2200 at five and six seconds. Check out SpaceWeather.com andArcticPhoto.no for more views.
Chad Blakley / Lights Over Lapland
Chad Blakley said on Sunday that he had “an unbelievable night” at Sweden’s Abisko National Park. “As soon as the sun went down I realized that we were about to experience something special,” he told SpaceWeather.com. “The auroras have been dancing all night long and show no sign of stopping! I only came in because 32 gigabytes of memory cards were full and all three batteries were dead!” Click on over to Blakley’s Vimeo page for a time-lapse video version of this imagery, and check out SpaceWeather.com for more from Abisko.
INCOMING CME? Yesterday, Nov. 9th around 1330 UT, a magnetic filament in the vicinity of sunspot complex 1342-1343 erupted, producing a M1-class solar flare and hurling a CME into space. The Solar and Heliospheric Observatory (SOHO) recorded the progress of the expanding plasma cloud:
Although the eruption was not squarely aimed at Earth, the CME is likely to deliver a glancing blow to our planet’s magnetic field on Nov. 11th or 12th. This could add to the impact of another CME already en route. The earlier cloud was propelled by a filament eruption (movie) on Nov. 7th and is also expected to deliver a glancing blow on Nov. 11th.
Analyses of these events are still preliminary, and the forecast may change. For now it is safe to say that high-latitude sky watchers should be alert for auroras on Nov. 11-12.
CME IMPACT: A CME hit Earth’s magnetic field on Oct. 24th at approximately 1800 UT (02:00 pm EDT). Acording to analysts at the Goddard Space Weather Lab, the impact caused a strong compression of Earth’s magnetic field, allowing solar wind to penetrate all the way down to geosynchronous orbit for a brief period between 19:06 UT and 19:11 UT. Earth-orbiting spacecraft could have been directly exposed to solar wind plasma during that time.
The impact also sparked a geomagnetic storm, underway now. Geir Øye sends this picture from Ørsta, Norway:
“The sky was brightly illuminated by auroras this evening,” says Øye. “The picture, above, was taken at 19.20 UT [just after the most extreme compression of the magnetosphere].”
High-latitude sky watchers should remain alert for auroras as Earth’s magnetic field continues to reverberate from the CME impact. The best time to look is usually during the hours around local midnight.
NIGHT TO REMEMBER: A coronal mass ejection (CME) hit Earth’s magnetic field around noon Universal Time on Sept. 26th. The impact set the stage for a night to remember. As soon as darkness fell over Scandinavia, auroras filled the sky with such intensity that they were visible through rain clouds. Fredrik Broms photographed the scene from Kvaløya, Norway:
“These were some of the most amazing auroras I have ever seen,” says Broms, a longtime observer of the Arctic lights. “The colours were absolutely stunning with purple and deep blood-red in addition to the green. It was a night I will never forget!
Sky watchers at the highest latitudes should remain alert for auroras as Earth’s magnetic field continues to reverberate from the CME impact.
MAJOR X-FLARE + CME: Yesterday, Earth-orbiting satellites detected a long-duration X1.4-class solar flare coming from sunspot 1302 on the sun’s eastern limb. The blast, which peaked at 1100 UT on Sept. 22nd, produced a significant coronal mass ejection (CME). Using data from the SOHO-STEREO fleet of spacecraft, analysts at the Goddard Space Weather Lab have modeled the trajectory of the CME and concluded that the body of the cloud will not hit Earth. A minor glancing encounter with the outskirts of the CME is, however, possible on Sept. 25th