Have you ever imagined yourself under a night sky, illuminated by waves of green, red and blue lights? This dazzling spectacle, known as the aurora borealis in the northern hemisphere and the aurora australis in the southern hemisphere, is one of the most impressive natural phenomena on the planet. But how do these magical lights appear in the sky?
Auroras result from the interaction between the solar wind – charged particles emitted by the Sun – and the Earth’s magnetic field. When these particles reach our planet, they collide with the magnetosphere and are driven towards the poles. Upon reaching the ionosphere, they collide with oxygen and nitrogen atoms, releasing energy in the form of photons. The color of the aurora depends on the gas involved and the altitude:
- Verde: Oxygen, between 100 and 300 kilometers.
- Red: Oxygen, above 300 kilometers.
- Blue or violet: Nitrogen, at lower altitudes.
The term “aurora” was coined by Galileo Galilei in 1619, inspired by the Roman goddess of dawn, believing that the lights were a reflection of the Sun in the atmosphere, a theory that later turned out to be wrong.
To watch this phenomenon, the best locations include Norway, Sweden, Finland, Iceland, Canada and Alaska. Winter is the best time, as longer, darker nights increase the chances of visibility. An interesting tip is to count 27 days since the last strong aurora, as this interval coincides with the time it takes for the Sun to complete one rotation, linking solar activity to the formation of auroras.
This is the ideal time to plan your trip, as we are in the solar cycle that will peak in 2025. Discover more about the solar wind and what makes it essential to this natural spectacle.
If you’re looking for an unforgettable phenomenon, perhaps it’s time to look up at the sky and let yourself be dazzled by the northern lights and southern lights.
Also read:
