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| The sun’s magnetic field has fully reversed its polarity, marking the midpoint of Solar Cycle 24, which will be completed in 11 years time |
The sun has
"flipped upside down", with its north and south poles reversed to
reach the midpoint of Solar Cycle 24, Nasa has said.
Now, the
magnetic fields will once again started moving in opposite directions to begin
the completion of the 22 year long process which will culminate in the poles
switching once again.
"A
reversal of the sun's magnetic field is, literally, a big event," said
Nasa’s Dr. Tony Phillips.
"The
domain of the sun's magnetic influence (also known as the 'heliosphere')
extends billions of kilometers beyond Pluto. Changes to the field's polarity
ripple all the way out to the Voyager probes, on the doorstep of interstellar
space."
To mark the
event, Nasa has released a visualisation of the entire process.
At the
beginning, in 1997 the video shows the sun in Solar Cycle 23 with its positive
polarity on the top (the green lines), and the negative polarity on the bottom
(the purple lines).
Each set of
lines gradually move toward the opposite pole, showing a complete flip around
2002, completing the sun's previous cycle.
Both set of
lines representing the opposing magnetic fields then begin to work their way
back, to culminate in the latest flip.
"At
the height of each magnetic flip, the sun goes through periods of more solar
activity, during which there are more sunspots, and more eruptive events such
as solar flares and coronal mass ejections," said Nasa’s Karen C. Fox.
"Cosmic
rays are also affected," added Dr.
Phillips. "These are high-energy particles accelerated to nearly light
speed by supernova explosions and other violent events in the galaxy."
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