An aurora is a spectacular sight with its dazzling curtains and brightly colored streaks of light. There are aurora borealis (the northern lights), but there is also aurora australis (the southern lights).
If you don’t manage to get a sight of the event, you’ll never forget it.
A common explanation for the aurora is that it is caused by “sun particles” striking our atmosphere. Except in a few rare circumstances, it is incorrect. So how did this natural wonder come to be?
When energetic charged particles hit atoms in the upper atmosphere, we see the aurora. Even though the aurora frequently occurs in conjunction with solar explosions, it is incorrect to assume that these energetic particles originate on the Sun.
Because of Earth’s magnetic attraction, electrically charged particles in space orbiting the planet are propelled around it with great precision. Usually, the Earth’s magnetic field remains constant at the surface, but it changes intensity and direction when the auroras show up.
It’s called a magnetic substorm, triggered by a fast interference in the magnetic field in the vicinity of Earth.
What is a Substorm?
We must first study plasma to comprehend how a substorm is triggered. In plasma, many atoms have been split apart into ions and electrons, forming a gas.
Both the Sun and other stars are made up of gases in a plasma state at their highest levels. The solar wind is a stream of plasma gas emitted by the Sun.
Plasma acts distinctly from the gases we encounter in our daily lives. Nothing occurs when you wiggle a magnet about your kitchen. The kitchen’s air is mainly composed of electrically neutral atoms therefore the rotating magnet has little effect.
Things are a little different because of its electrically charged particles when it comes to plasma. As a result, if your home was filled with plasma, a simple magnetic wave might cause it to move.
This interaction occurs when solar wind plasma arrives at the Earth and encounters the planet’s magnetic field.
Plasma usually moves smoothly along the magnetic field lines, but not across them, in the vast majority of instances.
To put it another way, solar wind will be redirected away from our atmosphere on its journey to Earth.Field lines are dragged out into an extended shape on the night side known as the magnetotail by the solar wind.
A slight breakdown in the structure of magnetic field lines may occur when flowing plasma mixes together magnetic fields from various areas.
When magnetic reconnection occurs, a new magnetic configuration is established, and, most crucially, a massive quantity of energy is unleashed.
The Sun’s outer atmosphere experiences these occurrences regularly, resulting in an explosion of energy and ejecting coronal mass ejections (CMEs) of magnetized gas.
When a coronal mass ejection hits Earth, it may set off a reconnection in the magnetotail, releasing energy that fuels electrical currents in the vicinity of Earth: a substorm. During this process, electrons are accelerated to very high energy by the solid electric fields.
Reconnection may have enabled some of these electrons to enter near-Earth space, but their acceleration in the substorm is essential to the aurora’s function.
The magnetic field then directs these particles upwards into the sky, carrying them far above the polar regions by the air currents.
Auroras form when these atoms clash with oxygen and nitrogen atoms in the upper atmosphere.
Doris’s passion for writing started to take shape in college where she was editor-in-chief of the college newspaper. Even though she ended up working in IT for more than 7 years, she’s now back to what he always enjoyed doing. With a true passion for technology, Doris mostly covers tech-related topics.