View Full Version : Space Weather
March 30th, 2012, 04:46 AM
RETURN OF THE SUNSPOT: Sunspot AR1429, the source of many strong flares and geomagnetic storms earlier this month, is about to re-appear following a two-week trip around the backside of the sun. Magnetic loops towering over the sun's NE limb herald the sunspot's approach:
Earlier today, NASA's Solar Dynamics Observatory photographed plumes of plasma rising and falling over the limb: movie. Moreover, a pair of solar flares (C5- and C7-class) in the sunspot's towering magnetic canopy caused waves of ionization to ripple through the high atmosphere over Europe.
While sunspot AR1429 was transiting the farside, it erupted multiple times. Between March 23rd and March 27th, the Solar and Heliospheric Observatory (SOHO) recorded four coronal mass ejections, each racing away from the sun faster than 3 million mph:
April 18th, 2012, 04:59 AM
LYRID METEOR SHOWER: Earth is approaching the debris field of ancient Comet Thatcher, source of the annual Lyrid meteor shower. Forecasters expect the shower to peak on April 21-22; a nearly-new moon on those dates will provide perfect dark-sky conditions for meteor watching. Usually the shower is mild (10-20 meteors per hour) but unmapped filaments of dust in the comet's tail sometimes trigger outbursts 10 times stronger. [video] [Lyrid chat]
GROWING SUNSPOT: What a difference a day makes. On April 16th, sunspot AR1460 did not exist. Twenty-four hours later it was twice as big as the planet Earth. This April 17th movie from NASA's Solar Dynamics Observatory shows sunspot genesis in action:
The sunspot's magnetic field is still too simple for strong flares, but if the expansion continues apace, instabilities could develop that lead to explosions. Readers with solar telescopes should keep an eye on AR1460. Solar flare alerts: text, voice.
SPECTACULAR EXPLOSION: Magnetic fields on the sun's northeastern limb erupted around 17:45 UT on April 16th, producing one of the most visually-spectacular explosions in years. NASA's Solar Dynamics Observatory (SDO) recorded the blast at extreme ultraviolet wavelengths:
The explosion, which registered M1.7 on the Richter Scale of solar flares, was not Earth-directed, but it did hurl a CME into space. Analysts at the Goddard Space Weather Lab have analyzed the trajectory of the cloud and found that it will hit NASA's STEREO-B spacecraft, the Spitzer space telescope, and the rover Curiosity en route to Mars. Planets Venus and Mars could also receive a glancing blow.
May 10th, 2012, 04:50 AM
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. Stay tuned.
May 19th, 2012, 06:21 AM
SOLAR ECLIPSE THIS WEEKEND: On Sunday, May 20th, the Moon will pass in front of the Sun, producing an annular solar eclipse visible across the Pacific side of Earth. The path of annularity, where the sun will appear to be a "ring of fire," stretches from China and Japan to the middle of North America:
July 4th, 2012, 05:37 AM
CHANCE OF X-FLARES: The chance of an X-flare today is increasing as sunspot AR1515 develops a 'beta-gamma-delta' magnetic field that harbors energy for the most powerful explosions. 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:
If any X-flares do occur today, they will certainly be Earth-directed. The sunspot is directly facing our planet. Radio blackouts, sudden ionospheric disturbances, and geomagnetic storms could be in the offing
July 15th, 2012, 07:55 AM
GEOMAGNETIC STORM: A fast-moving CME hit Earth's magnetic field on July 14th at approximately 1800 UT. The impact was not as strong as forecasters expected. Nevertheless, the blow compressed Earth's magnetosphere and sparked a mild (Kp=5) geomagnetic storm, in progress. So far, few sightings of auroras have been reported. Aurora alerts: text, voice.
The arrival of the CME shook Earth's magnetic field, which in turn induced electrical currents in the ground at Arctic latitudes. Rob Stammes measured the effect from his magnetic observatory in Lofoten, Norway:
Stammes has observed many CME strikes from his laboratory at the Polar Light Center. He says this one was not particularly strong, at least in terms of ground currents. Relatively weak ground currents are consistent with the muted displays of auroras in the aftermath of the strike.
July 29th, 2012, 06:08 AM
GEOMAGNETIC STORM WARNING: NOAA forecasters estimate a 45% chance of polar geomagnetic storms on July 29-30 in response to a high-speed solar wind stream buffeting Earth's magnetic field. Even stronger storming could occur on July 31st when a CME associated with yesterday's M6-flare arrives. High-latitude sky watchers should be alert for auroras for the next three nights
SOLAR ACTIVITY PICKS UP: Sunspot AR1532 is crackling with M-class solar flares. The latest, an M6-class eruption on July 28th (2056 UT), produced a bright flash of extreme ultraviolet radiation,
Update: Contrary to earlier reports, this explosion did produce a CME and the cloud is heading for Earth. According to a forecast track prepared by analysts at the Goddard Space Weather Lab, the CME will reach our planet on July 31st at 1500 UT (+/- 7 hours). Weak to moderate geomagnetic storms are possible when the cloud arrives. Solar flare alerts: text, voice.
August 18th, 2012, 05:41 AM
SIGNIFICANT SOLAR FLARE, NOT EARTH-DIRECTED: Magnetic fields snaking over the sun's northeastern limb erupted on August 18th around 01:02 UT. The M5.5 class eruption was not Earth-directed, but it could herald a significant uptick in geoeffective solar activity as the new active region turns toward Earth in the days ahead.
METEOR SMOKE: Researchers using NASA's AIM spacecraft have recently discovered that meteor smoke is a key ingredient of Earth's mysterious noctilucent clouds. "Meteor smoke" is the fine ashen debris left over when a meteoroid burns up in the atmosphere
August 31st, 2012, 06:23 AM
IONIZATION WAVES: Magnetic fields snaking around the sun's southeastern limb are crackling with C- and M-class solar flares. Extreme UV pulses from the flares are illuminating Earth's upper atmosphere, causing waves of ionization to ripple around the dayside of our planet.
August 31st, 2012, 07:48 AM
You might be the only one posting but you have readers so don't stop. I always liked Milky Way and Mars Bars. :lol2
Powered by vBulletin® Version 4.2.0 Copyright © 2013 vBulletin Solutions, Inc. All rights reserved.