Largest Solar Flare in Current Cycle Erupts on Sun

An extremely powerful solar flare, which is the largest in the current solar weather cycle, rocked the Sun on Tuesday, resulting in a coronal mass ejection (CME). But as the gigantic bursts of radiation occurred near the western limb of the Sun, it is unlikely to wreak any serious havoc on Earth.

The solar flare began at 3.48 am EDT and was recorded an X6.9 class on the three class scale used to measure the strength of solar flares. The recent solar flare is three times larger than the previous flare of this solar cycle -- the X2.2 that occurred on Feb. 15, 2011.

The weakest flares are rated C-class, medium sized flares are M-class while the strongest type of solar eruptions are rated X-class. Solar activity waxes and wanes over an 11-year sun weather cycle.

Solar flares occurred as a result of sun's magnetic field lines tangling up into knots. The knots build potential energy until they end up with a tipping point. After that the energy is converted into heat, light and the motion of charged particles, according to a Space.com report.

The solar flare ejects a cloud of plasma called a coronal mass ejection into space. The frequency of occurrence of solar flares varies, from several per day when the Sun is particularly "active" during the peak of solar cycle to less than one every week when the Sun is "quiet".

Scientists say the current solar cycle 24, which began in January 2008, is likely to last until around 2020. It is predicted that Solar Cycle 24 will peak in June 2013 with about 69 sunspots.

If the Tuesday eruption had taken place on the side of the sun facing Earth then it could have some serious consequences on Earth, like disrupting atmosphere, GPS and communications signals.

Though it cannot pass through Earth's atmosphere to harm humans on the ground, however, it can cause some radio communication blackouts. It can also produce increased solar energetic proton radiation -- enough to affect humans in space if they do not protect themselves.

But the flare happened near the western limb of the sun which wasn't facing Earth, so it may not be fully directed towards our planet.

"It was a big flare," said Joe Kunches, a space scientist with the US National Oceanic and Atmospheric Administration (NOAA)'s Space Weather Prediction Center. "We lucked out because the site of the eruption at the sun was not facing the Earth, so we will probably feel no ill effects."

The X6.9 flare succeeds a M2.5 class flare that took place during late Monday and another M3.5 class flare which was reported on Monday afternoon. Both the M-class flares happened near the western limb of the sun and the same region where the X6.9 flare erupted, so it is unlikely to impact earth.

Meanwhile, the space weather prediction center of the NOAA, a federal agency that focuses on the condition of the oceans and atmosphere, said the activity happening around the same region of the sun is expected to gradually decrease as the region rotates around the western limb.

But the space weather prediction center said there is a slight change for an isolated X-class flare and/or proton event for Wednesday. As the sun is moving towards another solar maximum that is likely in 2013, NASA scientists are expecting more flares to be coming, some small and some big enough to send their radiation all the way to Earth.

NOAA's space prediction center anticipates the Earth's magnetic field, also called geomagnetic field, to feel some disturbance during Wednesday, Thursday and Friday as a weak remnant of the Aug. 8 solar flare comes towards the planet. The center also expects the magnetic field to return to quiet conditions on Thursday and Friday.

In addition, the center said solar wind speed at the ACE spacecraft was about 600 km/s for Monday and Tuesday. But the center estimates the initial plane-of-sky speed to be about 1000 km/s due to the coronal mass ejection, which is a massive burst of solar wind, from the sun.

The recent class X flares happened during the recent solar cycle 24 are: a class X2 flare happened on Feb. 15; an X1 flare on March 9; an X7 flare on Aug. 9. During the previous solar cycle, an X9 flare occurred on Dec. 14, 2006.

In a huge solar storm back in 1859, telegraph offices worldwide were hit, some telegraph operators reported electric shocks, the telegraph systems malfunctioned and even paper caught fire. It is the strongest solar storm on record and is called the “Carrington Event", which is named after Richard Carrington, who viewed and reported on the solar flare of Sept. 1, 1859.