May’s auroras may have been strongest for 500 years, NASA says

The dazzling aurora display on May 10/11 was one of the strongest recorded in the past 500 years, according to a statement from NASA.

In another claim to record-breaking status, the British Geological Survey claimed the aurora display in the UK was the result of the most extreme and longest-lasting geomagnetic storm on record in 155 years.

And there’s a chance it could happen again.

“We will be studying this event for years,” said Teresa Nieves-Chinchilla, acting director of NASA’s Office of Space Weather Analysis (M2M). “It will help us test the limits of our models and understanding of solar storms.” The space agency added that they were “probably one of the strongest aurora displays recorded in the last 500 years”.

ForbesAurora Alert: Why you should now pack a bag for unexpected solar stormsfrom Jamie Carter

Simultaneous attacks

The solar superstorm on May 10/11 caused aurora borealis (northern lights) be visible as far south as Florida in the Northern Hemisphere, while aurora australis (southern lights) appeared as far north as New Zealand.

NASA first detected the beginnings of a solar storm on May 7, when two solar flares were found. An astonishing seven erupted over the next four days, all aiming coronal mass ejections—clouds of charged particles—at Earth. They traveled at different speeds and arrived simultaneously.

“The CMEs all arrived at the same time, and the conditions were right to create a truly historic storm,” said Elizabeth MacDonald, NASA’s heliophysics citizen science lead and a space scientist at the Goddard Space Flight Center in NASA in Greenbelt, Maryland.

The biggest since 2003

According to the BGS, May’s geomagnetic storm – caused by a series of successive solar flares and the CMEs that follow them – shares characteristics with some of the largest storms since 1869, including the Halloween geomagnetic storm of 2003. Activity daily geomagnetic has been recorded since 1869, he said.

Auroras are the result of the solar wind in space—charged particles from the sun—accelerating down the field lines of Earth’s magnetic field.

The Earth’s geomagnetic field is compared using horizontal magnetic field strength readings, which at Lerwick in the Sheland Isles, Scotland, typically measure around 30-50 nanoTesla (nT)m according to the BGS. On the evening of May 10, they peaked at 800 nT.

ForbesPictured: The world’s first jaw-dropping Aurora in the best ‘Solar Superstorm’ since 2003from Jamie Carter

The return of Aurora?

The sunspot that caused the flares and CME, called AR13364, is currently facing Venus, which threw a large X12-class solar flare on May 20. This was the most powerful of the current solar cycle. As the sun orbits Earth, AR13364 is expected to still be active, prompting warnings of more powerful geomagnetic storms.

A new article published in Nature says more powerful geomagnetic storms are expected in the next year or two as the sun heads toward “solar maximum,” a once-every-11-year peak in its magnetic activity.

I wish you clear skies and open eyes.