The dazzling display of aurora on May 10/11 was one of the strongest on record in the past 500 years, according to a statement from NASA.
In another claim of record-breaking status, the British Geological Survey claimed that the aurora display in the U.K. was the result of the most extreme and long-lasting geomagnetic storm recorded in the last 155 years.
And there’s a chance it could be about to happen again.
“We’ll be studying this event for years,” said Teresa Nieves-Chinchilla, acting director of NASA’s Moon to Mars (M2M) Space Weather Analysis Office. “It will help us test the limits of our models and understanding of solar storms.” The space agency added that they were “possibly one of the strongest displays of auroras on record in the past 500 years.”
Simultaneous Strikes
The solar superstorm on May 10/11 caused aurora borealis (northern lights) to be visible as far south as Florida in the northern hemisphere, while the aurora australis (southern lights) showed up as far north as New Zealand.
NASA first detected the beginnings of a solar storm on May 7, when two solar flares were found. A stunning seven went off in the following four days, all aiming coronal mass ejections—clouds of charged particles—in the direction of Earth. They traveled at different speeds and arrived simultaneously.
“The CMEs all arrived largely at once, and the conditions were just right to create a really historic storm,” said Elizabeth MacDonald, NASA heliophysics citizen science lead and a space scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
Largest Since 2003
According to the BGS, May’s geomagnetic storm—caused by a series of consecutive solar flares and the CMEs that follow them—shares characteristics with a few of the largest storms since 1869, with the most recent the 2003 Halloween geomagnetic storm. Daily geomagnetic activity has been recorded since 1869, it said.
Aurora are the result of the solar wind in space—charged particles from the sun—being accelerated down the field lines of the Earth’s magnetic field.
Earth’s geomagnetic field is compared using readings of its horizontal magnetic field intensity, which in Lerwick in the Sheland Islands, Scotland, typically measure around 30-50 nanoTesla (nT)m according to the BGS. On the evening of the 10 May, they peaked at 800 nT.
Return Of Aurora?
The sunspot that caused the flares and CMEs, called AR13364, is currently facing Venus, which it hurled a huge X12-class solar flare on May 20. That was the most poweful of the current solar cycle. As the sun rotates to face Earth, AR13364 is expected to still be active, prompting warnings of more possible powerful geomagnetic storms.
A new article published in Nature states that more, powerful geomagnetic storms are expected in the next year or two as the sun waxes towards “solar maximum,” a once-every-11-years peak in its magnetic activity.
Wishing you clear skies and wide eyes.
