Coronal mass ejection as viewed by the Solar Dynamics Observatory on 7 June 2011.
Credit: NASA/SDO
Two successive photos of a solar flare phenomenon evolving on the Sun. The solar disc was blocked in these photos for better visualisation of the flare.
Credit: Wikimedia
WASHINGTON: An unusual solar flare observed by a NASA space observatory on yesterday could cause some disruptions to satellite communications and power on Earth over the next day or so, officials said.
The potent blast from the Sun unleashed a firestorm of radiation on a level not witnessed since 2006, and will likely lead to moderate geomagnetic storm activity, according to the National Weather Service (NWS).
"This one was rather dramatic," said Bill Murtagh, program coordinator at the NWS's Space Weather Prediction Centre, describing the M-2 (medium-sized) solar flare.
"We saw the initial flare occurring and it wasn't that big but then the eruption associated with it - we got energy particle radiation flowing in and we got a big coronal mass injection," he said. "You can see all the materials blasting up from the Sun so it is quite fantastic to look at."
Effects are fairly small
NASA's solar dynamics observatory, which launched last year and provided the high-definition pictures and video of the event, described it as "visually spectacular," but noted that since the eruption was not pointed directly at Earth, the effects were expected to remain "fairly small".
"The large cloud of particles mushroomed up and fell back down looking as if it covered an area of almost half the solar surface," said a NASA statement.
Murtagh said space weather analysts were watching closely to see whether the event would cause any collision of magnetic fields between the Sun and Earth, some 150 million km apart.
Geomagnetic storm activity
"Part of our job here is to monitor and determine whether it is Earth-directed because essentially that material that is blasting out is gas with magnetic field combined," he said.
"In a day or so from now we are expecting some of that material to impact us here on Earth and create a geomagnetic storm. We don't expect it to be any kind of a real severe one but it could be kind of a moderate level storm."
The Space Weather Prediction Centre said the event is "expected to cause G1 (minor) to G2 (moderate) levels of geomagnetic storm activity tomorrow, June 8." Any geomagnetic storm activity will likely be over within 12-24 hours.
Historic solar minimum
"The Solar Radiation Storm includes a significant contribution of high energy protons, the first such occurrence of an event of that type since December 2006," the NWS said.
As many as 12 satellites and spacecraft are monitoring the heliosphere, and one instrument in particular on board NASA's lunar reconnaissance orbiter is measuring radiation and its effects.
"Certainly over the (two-year) lifetime of the mission this is the most significant event," said Harlan Spence, principal investigator with the cosmic ray telescope for the effects of radiation, or CRaTER. "This is really exciting because ironically when we were developing the mission initially we thought we would be launching closer to a solar maximum when these big solar particle events typically occur."
"Instead we launched into a historic solar minimum that took a long, long time to wake up. This is interesting and significant because it shows the Sun is returning to its more typical active state," he added.
