The physics that cause auroras originate at our nearest star. To understand why, we need to understand the sun’s own unusual physics.
Loading
Every 11 years, roughly, the sun’s magnetic field flips. If you were on the surface and holding a compass, you’d see north and south instantly switch places. That event is preceded by a dramatic increase in solar activity, known as the solar maximum.
As the sun moves towards solar maximum and grows more energetic, its magnetic fields become more strained. Some can twist and snag on each other.
Eventually, as the sun’s power grows, these “field lines” can break and reconnect, says Webb. When they do, they release a huge charge of energy and charged particles from the sun’s surface, which fly toward the Earth.
The Earth is protected by a relatively stable magnetic field. It shields us and our atmosphere from the sun’s stream of charged particles. Without it, we’d have no atmosphere and life could not exist.
On Friday night the field will again do its job and deflect nearly all the charged particles from the sun, but a few will sneak through.
Morning skies over Warnambool on Friday morning with magnificent aurora displays in pink and red.Credit: Madalaine Burke/Nine News
When they do, they will strike and excite electrons in the atoms of oxygen and nitrogen in the atmosphere. As those atoms release that energy, they will glow red and green – giving us the spectacular night show of the aurora.
Importantly, so long as the sky is clear, the aurora should be there – even if you can’t see it with the naked eye.
Read the full article here
