ALMOST-X FLARE AND CME: This morning, Jan. 23rd around 0359 UT, big sunspot 1402 erupted, producing a long-duration M9-class solar flare. The explosion’s M9-ranking puts it on the threshold of being an X-flare, the most powerful kind. NASA’s Solar Dynamics Observatory captured the flare’s extreme ultraviolet flash:
The Solar and Heliosphere Observatory (SOHO) and the STEREO-Behind spacecraft have both detected a CME rapidly emerging from the blast site. Analysts at the Goddard Space Weather Lab estimate a velocity of 2200 km. There is little doubt that the cloud is heading in the general direction of Earth. A preliminary inspection of SOHO/STEREO imagery suggests that the CME will deliver a strong glancing blow to Earth’s magnetic field on Jan. 24-25 as it sails mostly north of our planet.
ACTIVE SUNSPOT: New sunspot 1389 is crackling with M-class solar flares. NASA’s Solar Dynamics Observatory recorded this extreme UV flash from the active region at 2151 UT on Dec. 29th:
Although the sunspot is not directly facing Earth, its flares can affect our planet. X-rays and UV radiation from yesterday’s flares created waves of ionization in the upper atmosphere, altering the propagation of radio waves. The phenomenon was particularly strong over Europe where radio amateurs using low frequency receivers detected sudden ionospheric disturbances (“SIDs“) above Ireland and Italy. Student groups who wish to detect solar flares in this way can ask about obtaining a SID monitor from Stanford University.
NOAA forecasters estimate a 40% chance of more M-flares during the next 24 hours. There’s also a 5% chance of X-flares
CME TARGETS MARS, EARTH: New sunspot 1387 erupted during the late hours of Christmas Day, producing an M4-class flare and hurling a CME toward Earth and Mars. Click to view an animated forecast track prepared by analysts at the Goddard Space Weather Lab:
The CME is expected to deliver a glancing blow to Earth’s magnetic field on Dec. 28th at 1200 UT and a direct hit to the planet Mars on Dec. 30th at 1800 UT. Using onboard radiation sensors, NASA’s Curiosity rover might be able to sense the CMEwhen it passes the rover’s spacecraft en route to Mars. Here on Earth, NOAA forecasters estimate a 30-to-40% chance of geomagnetic storms on Dec. 28th when the CME and an incoming solar wind stream (unrelated to the CME) could arrive in quick succession. High-latitude sky watchers should be alert for auroras on Wednesday night.
UPDATE: The chances of a geomagnetic storm on Dec. 28th improved today when a second CME left the sun, this one even more squarely directed toward Earth. Ananimated forecast track shows the cloud reaching our planet on Dec. 28th at 20:22 UT.
CHRISTMAS EVE ERUPTION: A filament of magnetism connected to sunspot AR1386 erupted during the early hours of Dec. 24th. Extreme UV-wavelength cameras onboard the Solar Dynamics Observatory recorded the picturesque blast:
The C5-class eruption hurled a billion-ton coronal mass ejection (CME) into space, but not toward Earth. With the cloud sailing wide-left of our planet, Christmas geomagnetic storms are unlikely. Nevertheless, this active region merits watching as it turns toward Earth in the days ahead, possibly positioning itself for the first storms of 2012.
ERUPTION: The day before Thanksgiving, however, was not so quiet. On Nov. 23rd, a magnetic filament wrapping around the sun’s NW limb rose up and erupted. Click on the arrow to play the movie recorded by NASA’s Solar Dynamics Observatory:
The eruption hurled a cloud of plasma (a “CME”) into space but not toward Earth. Because of the blast site’s high-northern location on the sun, the cloud flew up and out of the plane of the solar system; no planets will be affected.
SOLAR BLAST:A magnetic prominence dancing along the sun’s southeastern limb became unstable on Nov. 15th and slowly erupted. NASA’s Solar Dynamics Observatory recorded the event, which unfolded over a period of thirteen hours:
The eruption hurled a cloud of plasma (CME) toward Venus. According to a forecast track created by analysts at the Goddard Space Weather Lab, the cloud should reach the second planet on Nov. 17th. Venus has no global magnetic field to protect it from CMEs. The impact will likely strip a small amount of atmosphere from the planet’s cloudtops.
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.
CHANCE OF FLARES: NOAA forecasters have upgraded the chance of X-class solar flares today to 20%. The source would be AR1339, one of the biggest sunspots in many years. The active region rotated over the sun’s eastern limb two days ago and now it is turning toward Earth.
The sunspot has already unleashed one X-flare on Nov. 3rd around 2027 UT. A movie from NASA’s Solar Dynamics Observatory shows the extreme ultraviolet flash:
The flare created waves of ionization in Earth’s upper atmosphere, altering the normal propagation of radio waves over Europe and the Americas. In Ireland, the flare’s effect was felt even after dark.
A cloud of plasma or “CME” raced away from the blast site at 1100 km/s. The CME is not heading for Earth. It is, however, heading for Mercury and Venus. Click on the arrow to view a movie of the CME’s forecast track:
Analysts at the Goddard Space Weather Lab say the CME will hit Mercury on Nov. 4th around 16:14 UT. NASA’s MESSENGER probe in orbit around Mercury will be monitoring the effects of the impact. If the CME overwhelms Mercury’s relatively weak magnetic field, it could scour material off the planet’s surface creating a temporary atmosphere and adding material to Mercury’s comet-like tail. The CME should hit Venus on Nov. 5th; the gossamer cloud will probably break harmlessly against the top of planet’s ultra-dense atmosphere.
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.
SPACE WEATHER FORECAST FOR MARS: A bright CME blasted off the sun yesterday, Oct. 22nd, and it appears to be heading for Mars. Analysts at the Goddard Space Weather Lab expect the cloud to reach the Red Planet on Oct. 26th (forecast track). A brief discussion of what CMEs can do to Mars follows this SOHO image of the eruption:
Mars has a unique response to solar storms shaped by the planet’s strange magnetic topology. Unlike Earth, which has a global magnetic field, Mars is patchily covered by dozens of “magnetic umbrellas”–remnants of an over-arching planetary field that decayed billions of years ago. When Mars gets hit by a CME, the resulting magnetic storms take place in the umbrellas. Circumstantial evidence collected by Mars Global Surveyor in the 1990s suggests that the tops of the umbrellas light up with bright ultraviolet auroras during such storms. Because the structures are distributed around the planet, these auroras can appear even at the equator.
Mars rovers and satellites should be alert for aurora equatorialis on Oct. 26th.
Bonus: Magnetic umbrellas are at the heart of one of Mars’s greatest mysteries: What happened to the atmosphere? Billions of years ago, the air on Mars was thick enough to protect vast expanses of water on the planet’s surface. Now, however, the atmosphere is 100 times thinner than Earth’s and the surface is bone dry. Some researchers believe that magnetic storms in the umbrellas could rip parcels of atmosphere away from Mars and propel air-filled magnetic bubbles into space. In this way, space weather could be directly responsible for the desiccation of the Red Planet.
