You might have wondered what was really going on up there if you've ever seen pictures of the night sky with green, pink, and purple light swirling around. That beautiful light is called the aurora borealis, or the northern lights. For hundreds of years, it has inspired myths and stories. But it's not magic or angry gods that are to blame. Our sun is where it all begins.

The sun is always sending tiny pieces of itself into space. The solar wind is a stream of charged particles, mostly electrons and protons. It travels millions of miles before finally hitting the Earth's magnetic field. That field is like a big shield that keeps most of the solar wind from hitting us, which is good for us. But the magnetic field isn't as strong near the North and South Poles. Some of those particles sneak in along the field lines and race down into the upper atmosphere.

They hit gas molecules like oxygen and nitrogen when they get there. When gas molecules collide, they gain energy and then let it go as light. Think of it like a sign with neon lights. Different gases make different colors. Oxygen tends to glow red at higher altitudes and green at lower altitudes, which is the most common color. When nitrogen is present, it makes blue and purple colors. The sun, which is ninety-three million miles away, powers the whole thing as a huge light show.

So when will you be able to see this happen? You need to be far north or far south, away from the lights of the city. Alaska, northern Canada, Iceland, Scandinavia, and Russia are some of the best places to visit in the northern hemisphere. It lasts from late August to early April because you need long, dark nights. The sky also needs to be clear. No matter how active the aurora is, clouds will block the view. The lights are also strongest in March and September, which are the months when the sun is at its highest point. That's when the solar wind usually hits Earth at the right angle.

You also need to keep an eye on what the sun is doing. There is an eleven-year cycle for the sun. At its peak, which is called solar maximum, there are more sunspots and solar flares. That means the solar winds will be stronger and the auroras will happen more often and be brighter. We're getting close to one of those peaks, so now is a great time to plan a trip.

In the end, the aurora borealis reminds us that our world is not alone. It is always dancing with the sun, with particles and magnetic fields. And if you ever get to stand under a curtain of green light that ripples, remember that the solar wind is saying hello to the upper atmosphere. That's a pretty cool idea.