X-FLARE! Big sunspot AR1520 unleashed an X1.4-class solar flare on July 12th. Because the sunspot is directly facing Earth, everything about the blast was geoeffective. For one thing, it hurled a coronal mass ejection (CME) directly toward our planet. According to a forecast track prepared by analysts at the Goddard Space Weather Lab, the CME will hit Earth on July 14th around 10:20 UT (+/- 7 hours) and could spark strong geomagnetic storms. Sky watchers should be alert for auroras this weekend.
The explosion also strobed Earth with a pulse of extreme UV radiation, shown here in a movie recorded by NASA’s Solar Dynamics Observatory:
The UV pulse partially ionized Earth’s upper atmosphere, disturbing the normal propagation of radio signals around the planet. Monitoring stations in Norway, Ireland and Italy recorded the sudden ionospheric disturbance.
Finally, solar protons accelerated by the blast are swarming around Earth. The radiation storm, in progress, ranks “S1” on NOAA space weather scales, which means it poses no serious threat to satellites or astronauts. This could change if the storm continues to intensify.
4TH OF JULY FIREWORKS: Chances of an X-flare today are increasing as sunspot AR1515 develops a ‘beta-gamma-delta’ magnetic field that harbors energy for the most powerful explosions. The sunspot’s magnetic canopy is crackling with almost-X class flares, the strongest so far being an M5-flare at 09:54 UT. Each “crackle” releases more energy than a billion atomic bombs, so these are 4th of July fireworks indeed.
The sunspot itself is huge, stretching more than 100,000 km (8 Earth-diameters) from end to end. This movie from NASA’s Solar Dynamics Observatory shows the behemoth growing and turning toward Earth over the past five days:
Another picture that dramatically illustrates the size of AR1515 is this 4th of July sunrise shot from Stefano De Rosa of Turin, Italy.
If any major eruptions do occur today, they will certainly be Earth-directed. The sunspot is directly facing our planet, so it is in position to cause radio blackouts, sudden ionospheric disturbances, and geomagnetic storms.
‘Big Bird’ On Sun? NASA Spies Coronal Hole That Looks Like ‘Sesame Street’ Fave (PHOTOS)
Posted: 06/04/2012 8:48 am Updated: 06/04/2012 10:19 am
This photo from NASA’s Solar Dynamics Observatory spacecraft, snapped on June 1, 2012, captures what looks like Big Bird on the surface of the sun. The feature is actually a coronal hole, a dark area of the sun’s upper atmosphere.
By: Mike Wall
Published: 06/01/2012 03:59 PM EDT on SPACE.com
A new photo from a NASA sun-watching spacecraft highlights a huge solar feature that looks a lot like the beloved Big Bird from the children’s television show “Sesame Street.”
The image, snapped today (June 1) by NASA’s Solar Dynamics Observatory (SDO) probe, actually shows a so-called coronal hole — an area where the sun’s corona, or outer atmosphere, is dark. But the resemblance to Big Bird, or one of his feathered kin anyway, is uncanny.
“I can’t get over how much this looks like Big Bird — but it is a coronal hole on the sun,” reads a Twitter post today by Camilla Corona SDO, the spacecraft’s rubber chicken mascot.
The rubber chicken’s Twitter feed is part of NASA’s social media outreach efforts. Officials pasted a picture of the “Sesame Street” character next to the ‘Big Bird’ coronal hole for comparison.
Coronal holes are associated with “open” magnetic field lines, which extend out into interplanetary space rather than arc back to the solar surface. Coronal holes are often found near the sun’s poles, Camilla added, and the high-speed solar wind — a stream of charged particles flowing from the sun’s upper atmosphere — is known to originate in them.
The super-speedy solar wind from the ‘Big Bird’ coronal hole will reach Earth between June 5 and June 7, Camilla said.
After remaining relatively quiet for several years, the sun has entered an active phase of its 11-year solar cycle, firing off a number of strong flares and coronal mass ejections (CMEs) — huge clouds of solar plasma — in the past several months.
CMEs that hit Earth inject large amounts of energy into the planet’s magnetic field, spawning potentially devastating geomagnetic storms that can disrupt GPS signals, radio communications and power grids for days, researchers say. These storms can also super-charge the northern and southern lights, generating brilliant shows for skywatchers at high latitudes.
Experts think the current cycle, known as Solar Cycle 24, will peak in 2013.
The $850 million SDO spacecraft launched in February 2010. The probe’s five-year mission is the cornerstone of a NASA science program called Living with a Star, which aims to help researchers better understand aspects of the sun-Earth system that affect our lives and society.
SOLAR ACTIVITY INTENSIFIES: Huge sunspot AR1476 is crackling with M-class solar flares and appears to be on the verge of producing something even stronger. The sunspot’s ‘beta-gamma-delta’ magnetic field harbors energy for X-class flares, the most powerful kind. Earth is entering the line of fire as the sunspot rotates across the face of the sun. Solar flare alerts:text, phone.
Earlier today, amateur astronomer Thomas Ashcraft of New Mexico detected strong shortwave radio bursts coming from the sunspot. Click to hear the “solar static” that roared out of his loudspeaker:
Dynamic spectrum courtesy of Wes Greenman, Alachua Radio Observatory
“The strongest burst so far occured around 1631 UT on May 9th,” reports Ashcraft. “I am observing at 28 MHz and 21.1 MHz. As I send this note I am hearing more bursting, indicating powerful magnetic dynamism within active region 1476.”
Solar radio bursts are caused by plasma instabilities that ripple through the sun’s atmosphere in the aftermath of powerful flares. With AR1476 poised for more eruptions, this ‘radio activity’ is likely to continue for days
CORONAL HOLE: A dark hole in the sun’s atmosphere (a ‘coronal hole’) is spewing a stream of solar wind toward Earth. The impact of the stream, expected on May 9-11, could add to the effect of the incoming CMEs, boosting the chances of strong geomagnetic activity later this week. NASA’s Solar Dynamics Observatory took this picture of the opening on May 8th:
Coronal holes are places where the sun’s global magnetic field opens up and allows some of the sun’s atmosphere to escape. The outflow of gas is the solar wind. NOAA forecasters estimate a 40% chance of geomagnetic activity on May 9-10 when the stream arrives (along with the CMEs of May 7th).
TWO INCOMING CMEs: A pair of solar eruptions on May 7th hurled coronal masss ejections (CMEs) toward Earth. Forecasttracks prepared by analysts at the Goddard Space Weather Lab suggests that clouds with arrive in succession on May 9th at 13:40 UT and May 10th at 07:54 UT (+/- 7 hours). The double impact could spark moderate geomagnetic storms. High-latitude sky watchers should be alert for auroras.
FARSIDE ACTIVITY: For more than a week, solar activity has been low. On April 26th around 0600 UT, an active region on the farside of the sun broke the calm with a powerful eruption. NASA’s Solar Dynamics Observatory recorded a massive cloud of plasma flying over the sun’s southwestern limb:
The same active region has since hurled three CMEs into space. The clouds will certainly miss Earth, but they might hit Mercury, which appears to be in the line of fire.
SUNSPOT GENESIS: The solar disk is peppered with sunspots and at least three of them are crackling with C-class solar flares. Make that four. A new sunspot, AR1465, has just broken through the stellar surface to join the action. Cai-Uso Wohler photographed the emergence from his backyard observatory in Bispingen, Germany:
NOAA forecasters estimate a 30% chance of an M-class flare during the next 24 hours. As the youngest and least stable of the sunspots, AR1465 is the most likely source. Stay tuned for solar activity
INCOMING PLASMA CLOUDS: On April 18th and 19th, a series of minor CMEs puffed away from the sun. Three of them are heading in our general direction. Analysts at the Goddard Space Weather Lab have prepared an animated forecast track of the ensemble:
According to the forecast, the clouds are going to hit Mercury, Earth, Mars and rover Curiosity en route to Mars. The impact on our planet, on April 22nd around 00:50 UT, is expected to be minor with auroras likely only at higher latitudes
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!”