The Northern Lights (Aurora Borealis)

The Northern Lights, scientifically known as the Aurora Borealis, are a stunning natural light display that shimmers across the sky, primarily in high-latitude regions. This ethereal phenomenon is a direct result of the interaction between the sun and Earth's atmosphere.

What Causes the Aurora?

The aurora is a celestial dance of light caused by collisions between electrically charged particles from the sun and gaseous particles in Earth's atmosphere. The sun constantly emits a stream of charged particles called the solar wind. While Earth's magnetic field largely protects us from this stream, some of these particles are funneled towards the poles.

As these charged particles from the solar wind collide with atoms and molecules of gases like oxygen and nitrogen in Earth's upper atmosphere, they excite these particles. This excitation process is similar to how a neon light works. When the excited gas particles return to their normal state, they release photons of light. The cumulative effect of billions of these collisions creates the vibrant, glowing curtains and arcs we see in the night sky.

Colors of the Aurora

The colors of the aurora are determined by the type of gas particles involved and the altitude at which the collisions occur. The most common color, a brilliant green, is produced by collisions with oxygen atoms at altitudes of about 60 miles (97 km). Higher-altitude oxygen collisions, at around 200 miles (322 km), can produce a rare red aurora.

The Northern Lights (Aurora Borealis)

Blue or purple hues are caused by collisions with nitrogen molecules. Because different altitudes and atmospheric compositions produce different colors, the Northern Lights often appear as a dynamic, multicolored spectacle. The specific shape and movement of the aurora are influenced by the shifting patterns of the Earth's magnetic field.

Where to See the Aurora

The best places to witness the Aurora Borealis are within the auroral oval, a ring-shaped zone surrounding the Earth's magnetic poles. Top destinations for aurora viewing include regions in Alaska, Canada, Greenland, Iceland, Norway, Sweden, and Finland. To increase your chances of seeing the lights, it is best to travel during the dark winter months and seek out locations with minimal light pollution. While the aurora is a continuous process, its visibility from the ground depends on a clear sky and strong solar activity. Auroral forecasts and apps can help you track the likelihood of a major display, making the hunt for this incredible natural wonder more successful.