What I Learned About the Northern Lights After Chasing Them in Tromsø

I’ve seen countless photos of the aurora, but nothing prepared me for the real thing. Standing in the freezing cold near Tromsø, Norway, watching those green curtains dance across the sky felt like a dream. I have to be honest, when I visited, I didn’t have a nice camera or a new phone. But my biggest takeaway was that you don't need a fancy gadget to fully enjoy a moment.

If you're like me, you probably have a lot of the same questions. So, I dug into the science behind the magic, and here’s a breakdown of what I learned. This isn't just about what the Northern Lights are—it's about understanding the cosmic phenomenon that makes them possible.

1. It All Starts with the Sun (Yes, Really!)

The Northern Lights aren't caused by anything happening on Earth. The show actually begins 93 million miles away on the surface of the Sun. Our star is a giant, fiery ball of gas, and it's constantly releasing a stream of charged particles—mostly electrons and protons—into space. This stream is called the solar wind.

2. Earth's Magnetic Shield: Our Invisible Protector

As the solar wind rushes towards Earth at incredible speeds, it hits an invisible force field: our planet's magnetic field. This magnetic field is like a giant, protective bubble that shields us from most of the dangerous particles.

But the field is weakest at the North and South Poles. Think of it like a funnel. The solar particles are drawn in and guided down the magnetic field lines towards the poles.

3. The Cosmic Collision

This is where the magic happens! As those charged particles from the sun enter Earth's atmosphere, they collide with atoms and molecules of gas, primarily oxygen and nitrogen. These collisions transfer energy, "exciting" the atoms to a higher energy state.

But atoms don't like to stay in this excited state. To return to normal, they release that extra energy in the form of light. Millions of these tiny bursts of light happening at the same time create the spectacular, dancing sheets of color we see in the sky.

The science behind the aurora

4. Why Are They So Many Colors?

I was lucky enough to see a vibrant green aurora, but sometimes they can be red, blue, or even purple. I thought it was just random, but it's actually about chemistry!

• Green: The most common color, green is produced by excited oxygen atoms.

• Red: A rarer color that looks absolutely stunning, red light is also from oxygen, but it happens at higher altitudes.

• Blue and Purple: These are caused by collisions with nitrogen molecules, usually at lower altitudes.

The aurora borealis as see from Galloway Township, New Jersey, Oct. 10, 2024.

Photo by the U.S Air National Guard

5. So, Is There a Southern Light?

This was one of my biggest questions! And the answer is a definite yes. The exact same phenomenon happens at the South Pole, where it's called the aurora australis, or the Southern Lights. They are just as beautiful but harder to see because there are fewer accessible landmasses near the South Pole. So while people travel to Norway, Iceland, or Alaska to see the aurora borealis, you'd have to go to places like New Zealand or Tasmania to see the aurora australis.

My Final Thoughts...

Understanding the science behind the aurora didn’t take away from its magic. If anything, it made me appreciate it even more. It’s a spectacular reminder that we are part of a massive, dynamic solar system, and sometimes, the universe puts on a show just for us.

Have you ever seen the Northern Lights? Share your experience in the comments below!

Ready to see the magic in action?

Now that you know the science behind the Northern Lights, you're ready for the next step.

Ready to read about what it was like to see them in person? Learn about my journey to Tromsø.

Want to learn how to capture them for yourself? Read my full guide on photographing the Northern Lights.