Every second,
one million tons of matter is blasted from the Sun
at the velocity of one million miles per hour,
and it's on a collision course
with Earth!
But don't worry,
this isn't the opening of a new Michael Bay movie.
This is The Journey of the Polar Lights.
The Northern and Southern Lights,
also known as the Aurora Borealis
and Aurora Australis, respectively,
occur when high energy particles from the Sun
collide with neutral atoms in our atmosphere.
The energy emitted from this crash
produces a spectacle of light
that mankind has marveled at for centuries.
But the particles journey isn't just as simple
as leaving the Sun and arriving at Earth.
Like any cross-country road trip,
there's a big detour
and nobody asks for directions.
Let's track this intergalactic voyage
by focusing on three main points of their journey:
leaving the sun,
making a pit stop in the Earth's magnetic fields,
and arriving at the atmosphere above our heads.
The protons and electrons creating the Northern Lights
depart from the Sun's corona.
The corona is the outermost layer
of the Sun's atmosphere
and is one of the hottest regions.
Its intense heat causes the Sun's hydrogen
and helium atoms to vibrate
and shake off protons and electrons
as if they were stripping off layers on a hot, sunny day.
Impatient and finally behind the wheel,
these free protons and electrons move too fast
to be contained by the sun's gravity
and group together as plasma,
an electrically charged gas.
They travel away from the sun
as a constant gale of plasma,
known as the solar wind.
However, the Earth prevents the solar wind
from travelling straight into the planet
by setting up a detour,
the magnetosphere.
The magnetosphere is formed
by the Earth's magnetic currents
and shields our planet from the solar winds
by sending out the particles around the Earth.
Their opportunity to continue the journey
down to the atmosphere
comes when the magnetosphere is overwhelmed
by a new wave of travellers.
This event is coronal mass ejection,
and it occurs when the Sun shoots out
a massive ball of plasma into the solar wind.
When one of these coronal mass ejections
collides with Earth,
it overpowers the magnetosphere
and creates a magnetic storm.
The heavy storm stresses the magnetosphere
until it suddenly snaps back,
like and overstretched elastic band,
flinging some of the detoured particles towards Earth.
The retracting band of the magnetic field
drags them down to the aurora ovals,
which are the locations
of the Northern and Southern Lights.
After travelling 93 million miles across the galaxy,
the Sun's particles finally produce
their dazzling light show with the help of some friends.
Twenty to two hundred miles above the surface,
the electrons and protons meet up
with oxygen and nitrogen atoms,
and they sure are happy to see each other.
The Sun's particles high five the atoms,
giving their energy
to the Earth's neutral oxygen and nitrogen atoms.
When the atoms in the atmosphere
are contacted by the particles,
they get excited and emit photons.
Photons are small bursts of energy
in the form of light.
The colors that appear in the sky
depend on the wavelength of the atom's photon.
Excited oxygen atoms are responsible
for the green and red colors,
where as excited nitrogen atoms produce
blue and deep red hues.
The collection of these interactions
is what creates the Northern and Southern Lights.
The polar lights are best seen on clear nights
in regions close to magnetic north and south poles.
Nighttime is ideal
because the Aurora is much dimmer than sunlight
and cannot be seen in daytime.
Remember to look up to the sky
and read up on the Sun's energy patterns,
specifically sunspots and solar flares,
as these will be good guides
for predicting the auroras.