Around 12:06 p.m EDT on Sept 10, 2017, NASA’s Solar Dynamics Observatory captured an image of the sun unleashing a massive solar flare from a recently active region. Solar flares are powerful bursts of radiation. Harmful radiation from a flare cannot pass through Earth's atmosphere to physically affect humans on the ground, however — when intense enough — they can disturb the atmosphere in the layer where GPS and communications signals travel. Per NASA,
This flare is classified as an X8.2-class flare. X-class denotes the most intense flares, while the number provides more information about its strength. An X2 is twice as intense as an X1, an X3 is three times as intense, etc.
The X9.3 flare was the largest flare so far in the current solar cycle, the approximately 11-year-cycle during which the sun’s activity waxes and wanes. The current solar cycle began in December 2008, and is now decreasing in intensity and heading toward solar minimum. This is a phase when such eruptions on the sun are increasingly rare, but history has shown that they can nonetheless be intense.
This flare is the capstone on a series of flares from Active Region 2673, which was identified on Aug. 29 and is currently rotating off the front of the sun as part of our star’s normal rotation.
The flare was captured in the following NASA’s Goddard Space Flight Center video.
NASA’s Solar Dynamics Observatory captured this image of the solar flare:
The National Oceanic and Atmospheric Administration signals X8.2 (R3-STRONG) X-RAY EVENT OBSERVED AT 10/1606 UTC. Primary areas impact includes ‘large portions of sunlit side of earth’. Possible effects include wide spread HF radio blackouts and navigation degradation through GPS (loss in signal).
As SWL.com notes, "yesterday's X8.2 (R3-strong) solar flare from sunspot region 2673 was one of the most spectacular solar flares we have ever seen. Not only was this the second strongest solar flare of the current solar cycle, it also launched an extremely fast and broad coronal mass ejection:
Following the flare, we quickly reached the strong S3 solar radiation storm level which only takes place about 10 times during a 11 year solar cycle. Possible effects of the ongoing S3 solar radiation storm are: degraded HF radio propagation at polar regions and navigation position errors, satellite effects on imaging systems and solar panel currents, significant radiation hazard to astronauts on extra-vehicular activity (EVA) and high-latitude aircraft passengers.
The coronal mass ejection is as far as we can remember one of the fastest coronal mass ejections of the current solar cycle as we measured the ejecta at a whopping 2,700km/s to 2,800km/s! To compare: The X28 coronal mass ejection from 4 November 2003 left the Sun at 2,400km/s! Goes to show this is an extreme coronal mass ejection that would without a doubt cause intense geomagnetic storming if it would have been launched directly at Earth.
SOHO/LASCO imagery shows an impressive asymmetrical full halo coronal mass ejection which means the outer edges of the solar plasma cloud are directed straight at (or away) from the observing space craft. It is therefor hard to say if this edge is directed towards the front side, the far side or both but taking into account the monstrous coronal wave and the jump in the low-energy EPAM protons, we are fairly confident that we are going to see at least a shock passage or a glancing blow at Earth. You can see the coronal wave in the tweet that we posted yesterday.
The X8.2 solar flare is highly eruptive with a fast and broad coronal wave. Wow! pic.twitter.com/ZYhVrAu9D7— SpaceWeatherLive (@_SpaceWeather_) September 10, 2017
As SWL adds, while the flanks of a coronal mass ejection are always a bit slower than the bulk, the transit time should still be around one and a half day or about 36 to 40 hours (calculated with SARM) which puts the expected impact time of this coronal mass ejection at 06:00 UTC on 12 September 2017 with a plus/minus of 6 hours. The NOAA SWPC has a much later impact time, late on September 13.
Subsequent coronagraph imagery analysis has been concluded. The full halo coronal mass ejection (CME) was so powerful and widespread, there actually appears to be an Earth directed component, most evident when viewing the LASCO C3 (blue color) video. If so, an impact to the earth's geomagnetic field may be possible as soon as tomorrow.
According to the latest tracking models, the edge of the large CME may deliver a glancing blow to our geomagnetic field by Sept. 13th. This combined with an anticipated coronal hole stream may help to enhance activity. A Moderate (G2) storm watch will be in effect.