“Auroral beads” imprisoned in Finland in October 2014 just for a strong display of aurora.
Next time you are waiting for the aurora borealis or northern lights to arrive – perhaps in Alaska, northern Canada, Iceland, northern Norway, Finland or Sweden – look out for “auroral beads”, because there are some especially about can happen.
NASA’s space fleet has helped to discover the truth about a very special kind of aurora, also called ‘northern lights’ in the northern hemisphere.
Described as “like a glowing pearl necklace”, the phenomenon of “auroral beads” can sometimes be seen just in front of large auroral displays, but so far, scientists have speculated.
What are aurora?
Aurora are a natural celestial phenomenon near the Arctic Circle (aurora borealis or northern lights) and Antarctic circle (aurora australis or southern lights).
They are caused by charged particles of the sun that are trapped and accelerated by the earth’s magnetosphere to interact with atoms in the upper atmosphere.
What are ‘auroral beads?’
They are beads that illuminate the sky like single pearls in a glowing ‘auroral necklace’, according to scientists.
Most often, they appear when aurora begins to brighten, and even if they are a mystery in themselves, it is thought that they can cause – or indicate – impressive images of aurora.
What causes ‘auroral beads?’
They are caused by turbulence in the plasma in the space around the earth, and not in the upper atmosphere of the earth, as was previously thought.
“Now we know for sure that the formation of these beads is part of a process that precedes the triggering of a substorm in space,” said Vassilis Angelopoulos, lead researcher at THEMIS at the University of California, Los Angeles. “This is an important new piece of the puzzle.”
While the plasma emitted by the sun interacts with the Earth’s magnetic field, it causes floating bubbles of plasma behind the Earth, scientists say. Similar to a lava lamp, they explain that imbalance in the drift between the bubbles and heavier plasma in the magnetosphere makes fingers 2,500 miles wide, extending toward Earth.
That’s what causes ‘auroral beads’. The results were published today in the Geophysical Research Letters and Journal of Geophysical Research: Space Physics.
Northern lights show over Jokulsarlon Glacier Lagoon, Iceland.
What is NASA’s THEMIS mission?
It is a fleet of three spacecraft orbiting the Earth. Since its launch in 2007, THEMIS has taken detailed measurements through the magnetosphere to help scientists understand the causes of the sub-storms that lead to auroras.
By modeling the vicinity of near Earth on scales of tens of miles to 1.2 million miles, THEMIS scientists were able to show the details of how auroral beads form.
“There are a lot of very dynamic, very small-scale structures that people see in the auroras that are difficult to connect to the larger image in space because they happen very quickly and on very small scales. , “said Kareem Sorathia, lead author on one of the new papers and scientist at NASA’s Center for Geospace Storms headquartered at Johns Hopkins Applied Physics Laboratory. “Now that we can use global models to characterize and research them, that opens up a lot of new doors.”
I wish you clear skies and wide eyes.
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