Boa tarde.
Alguem notou perturbações nas telecomunicações e GPS,cá em Portugal?
On the evening of Tuesday, July 5, a comet flew into the sun. Such comets are not unusual, and they're called "sungrazers" since they come so close to the star that it is believed they evaporate and disappear. However, no one has actually seen the end of that journey, since the comets are best seen in cameras from SOHO (SOlar and Heliospheric Observatory) that block out the bright disk of the sun itself.
But this was different. For the first time ever, SDO (Solar Dynamics Observatory) captured a 20-minute movie of the comet streaking directly in front of the sun. It's not immediately obvious, but if you watch the movie closely, you'll see a line of light appear in the right and move across to the left.
At its most basic, the movie has scientists excited since it's a "first," but additional analysis of the data may hold more clues about the fate of the comet. Most likely, given the intense heat and radiation, the comet simply evaporated away completely.
http://www.nasa.gov/mission_pages/sunearth/news/comet-streaks-sun.html
Ocorreu hoje e ontem dois flares solares direccionados para a Terra. Um M1 e um M6.6
Fortes e provavelmente vão causar fortes auroras boreais, que poderão ser vísiveis até bastante sul (segundo a previsão norte da Inglaterra e Alemanha)
No melhor cenário poderá trazer as auroras por instantes até ao horizonte norte do norte de Portugal), mas acho que só seriam visiveis com céu limpo e em zonas rurais com um horizonte norte escuro e sem obstruções. Provavelmente isso nem irá ocorrer. Mas valerá a pena estar atento.
Ainda assim, estes flares são pequenos comparados com um flare X que seria o necessário para trazer auroras ainda mais a sul e causar disrupções nas redes eléctricas e comunicações. Um exemplo disso foi o X20 que ocorreu em 2001, durante o qual vi uma aurora boreal dos arredores de Braga.
www.spaceweather.com
STRONG SOLAR ACTIVITY: For the third day in a row, active sunspot 1261 has unleashed a strong M-class solar flare. The latest blast at 0357 UT on August 4th registered M9.3 on the Richter Scale of Flares, almost crossing the threshold into X-territory (X-flares are the most powerful kind).
The number of energetic protons around Earth has jumped nearly 100-fold as a result of this event. Stay tuned for updates.
INCOMING CLOUDS: At least two coronal mass ejections (CMEs) are now en route to Earth, propelled toward us by eruptions in the magnetic canopy of sunspot 1261 on August 2nd and 3rd. Analysts at the GSFC Space Weather Lab have just produced a new 3-D model of the advancing CMEs. Click on the image to set the clouds in motion:
ONE DOWN, TWO TO GO: As predicted by analysts at the GSFC Space Weather Lab, the first of three CMEs produced by the recent spate of flare activity reached Earth during the late hours of August 4th. The impact was weak and is not expected to produce strong geomagnetic storms. Two more CMEs are still on the way and, as described below, they may have merged into a single cloud that could produce significant storming when they reach Earth on August 5th at 10:00 UT (plus or minus 7 hours). A new model of all 3 CMEs is now available; stay tuned for updates.
MAJOR SOLAR FLARE: This morning at 0805 UT, sunspot 1263 produced a powerful X7-class solar flare. NASA's Solar Dynamics Observatory captured the explosion's extreme ultraviolet flash:
http://spaceweather.com/swpod2011/09aug11/x7.mov?PHPSESSID=d1gqhupmv0rcpjg2us4mut27q1
The brunt of the explosion was not Earth directed. Nevertheless, a minor proton storm is in progress around our planet, which could affect satellites in high-altitude orbits. Also, radiation from flare created waves of ionization in Earth's upper atmosphere, briefly disrupting communications at some VLF and HF radio frequencies.
SOHO coronagraphs show a CME emerging from the blast site. The cloud will probably miss Earth. At this time, however, we cannot rule out a glancing blow from the flank of the CME on or about August 11th. Stay tuned for updates.
more data: from Rob Stammes of Laukvik, Lofoten, Norway; from Andy Smith of Devon, United Kingdom.
STRONG SOLAR ACTIVITY: Sunspot 1283 is crackling with solar flares. Yesterday, Sept. 6th, the active region produced an M5.3-class eruption at 0150 UT followed by a X2.1-class event at 2220 UT. NASA's Solar Dynamics Observatory recorded this extreme UV flash from the X-flare:
The flares produced waves of ionization in Earth's upper atmosphere, briefly altering the propagation of low-frequency radio signals around our planet. Moreover, the two eruptions hurled clouds of plasma (CMEs) in our general direction. A preliminary analysis of SOHO and STEREO imagery suggests that the CMEs could sail substantially north of Earth, delivering a glancing blow to Earth's magnetic field as they pass. ETA: Sept. 8-10. Stay tuned for updates.
COMET AND CME: A comet discovered by amateur astronomers on Friday, Sept. 30th, disintegrated in spectacular fashion the very next day when it plunged into the sun. The Solar and Heliospheric Observatory recorded the comet's last hours. The end was punctuated by an unexpected explosion:
Watch the movie again. The timing of the CME so soon after the comet dove into the sun suggests a link. But what? There is no known mechanism for comets to trigger solar explosions. Before 2011 most solar physicists would have discounted the events of Oct. 1st as pure coincidence--and pure coincidence is still the most likely explanation. Earlier this year, however, the Solar Dynamics Observatory (SDO) watched another sungrazer disintegrate in the sun's atmosphere. On July 5, 2011, the unnamed comet appeared to interact with plasma and magnetic fields in its surroundings as it fell apart. Could a puny comet cause a magnetic instability that might propagate and blossom into a impressive CME? The question is not so crazy as it once seemed to be.