A major flare shot off the sun Friday July 14, pummeling Earth with the biggest solar radiation storm in almost six years A major flare shot off the sun Friday July 14, pummeling
Earth with the biggest solar-radiation storm in almost six years. The barrage of protons spewing off the sun disrupted some satellites and shortwave radio communication and prompted a call to delay a Russian space launch.Meanwhile, Earth was enveloped Friday by its second major geomagnetic storm in two days, caused by solar flares earlier in the week.
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A third big magnetic storm major to possibly severe -- was expected to hit Saturday afternoon July 15 as a result of Fridays flare and related mass ejection of electrified gas from the suns corona at 3 million m.p.h. (4.8 million kilometers per hour). It could push the northern and southern
lights away from the poles and down to mid latitudes. The National Oceanic and Atmospheric Administration (NOAA) called Fridays events "one of the largest solar flares and associated radiation storms seen in recent years."
Most of the activity is hitting Earth courtesy of sunspot region 9077, one of several active
sunspot groups that have produced several major, or X-class, flares in the past week."This sunspot region is only into the first week of two weeks facing us," said Dave Speich, a space scientist at NOAAs Space Environment Center in Boulder, Colorado.
"So we have another week this thing could produce more events and send more several more
solar-radiation storms and geomagnetic storms our way," he said. "Weve got a train lining up at us a train of storms and disturbances."Fridays solar flare started at 6:03 a.m. Eastern Daylight Time (10:03 GMT) and peaked at 6:24 a.m. EDT (10:24 GMT), Speich said. Based on its X-ray intensity, it was a major or X-class flare rated at X5.9 on a scale that goes to X20.
The flare sent a barrage of protons toward Earth, triggering category S3 solar radiation storm conditions, which are major on a scale from minor S1 to extreme S5.
"It was the largest solar-proton event or solar-radiation storm weve seen in six years" since October 1994, Speich said. "The radiation storm is in progress and will go on several more days."
Speich said he was trying to contact Russian space authorities to suggest they delay Saturdays planned launch of the first two Cluster spacecraft designed, ironically, to study space weather.
The protons generated by Fridays flare can cause problems with spacecraft electronics, and the flare-generated geomagnetic storm expected to hit within a day or two "increases the density of the atmosphere so your launcher is fighting a much thicker atmosphere," Speich said. "This would be difficult to launch into."
During major solar-radiation storms, satellites can suffer upsets from proton impacts, noise in imaging devices and damage to exposed components.
"I received a call from the operator of a fleet of satellites that they were having trouble with the star trackers that orient their spacecraft," Speich said.
Protons from the intense solar wind can affect the light-detectors used by the devices to find stars and orient the satellites. Speich declined to identify the satellite company but said the affected spacecraft "were communications satellites."
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During S3 storms, astronauts are advised to reduce exposure, particularly during spacewalks, but there are no astronauts in space now.
S3 solar-radiation storms also can give passengers and crews on commercial jets at high latitudes radiation exposure equal to a chest X-ray. The atmosphere protects people on the ground.
Fridays flare also triggered category R3, or major radio blackout conditions on Earths daylit side for about two hours after its peak, Speich said. Such blackouts are typified by wide losses of shortwave communications and perhaps hour-long loss of radio contact and degradation of navigation systems for aviators and mariners.
Major and moderate solar flares on July 10 and 11 caused coronal mass ejections that triggered category G3, or major geomagnetic storm conditions Thursday and again Friday. Speich said forecasters were wrong when they earlier said that Thursdays geomagnetic storm was from the combination of the July 10 and 11 flares.
An even bigger geomagnetic storm from Fridays flare is expected to hit starting Saturday afternoon in U.S. time zones, but "the brunt will come in Saturday night and Sunday," Speich said. NOAA said it could last until Monday.
He said it should cause more radio blackouts and might make auroral lights visible down to latitudes of 40 degrees north and south, meaning they might be seen in Europe, much of Russia and Southern Hemisphere cities like Sydney and Santiago, he added. NOAA said the aurora also might be visible from Seattle, Denver, New York, Washington, D.C. and perhaps even into the southern states.
NASAs Goddard Space Flight Center hyped Fridays flare as a "record solar blast" and "the most intense blast of solar particles ever detected by the Solar and Heliospheric Observatory (SOHO) and the Advanced Composition Explorer (ACE) spacecraft."
Speich, however, said there have been much larger solar flares. The satellites only have been orbit since after the start of the current 11-year solar cycle, he noted.
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