(NEXSTAR) — Amid a massive solar storm, Americans as far south as Hawaii, Florida, and Texas have had the chance to see the northern lights. For some, it’s the first time in nearly two decades that conditions aligned to bring the aurora to their night skies.
If you saw the northern lights — either with your own eyes or with the help of your phone — you may have noticed an array of colors. But what causes the different shades of greens, reds, blues, and purples? It’s all about what’s hitting our atmosphere, and what it’s interacting with.
Northern lights are sparked by coronal mass ejections, or explosions of plasma and magnetic material shooting out of the sun, colliding with Earth’s magnetic field. As those ejections, known as CMEs, smack into our magnetic field, currents send particles flowing to the North and South Poles.
Those particles will ultimately interact with the gases in our atmosphere: oxygen and nitrogen. The excess energy created by those interactions, according to NASA, will cause a burst of light which we see as the aurora.
What color we experience depends on which gases are involved and where it happens.
Green northern lights, the most common, occur when particles interact with oxygen between 75 and 110 miles in altitude. If oxygen and nitrogen are “excited by the incoming particles” at the same altitude, we can see blue aurora, NASA explains.
Slight lower, 60 miles and below, an interaction with nitrogen will cause pink northern lights. Above 120 miles, interactions with oxygen spark red aurora.
When these colors mix together, they can create shades of purple, white, and various tones of pink, much like blending paint.
Although we may not always see the shimmering northern lights with our eyes, newer phone cameras are often more sensitive and able to capture them, even when we cannot. may be able to capture it due to their higher sensitivity compared to our eyes, as noted by Michael Bettwy, operations chief of NOAA’s Space Weather Prediction Center, last week.
“While the naked eye may not perceive it, on a clear night with few clouds, pointing your phone towards the sky may result in capturing a few images,” Bettwy remarked.
Explore Iceland (where the northern lights are frequently visible) suggests adjusting your phone’s settings to optimize photo quality. This may involve utilizing features such as “night mode” or adjusting the camera’s exposure time to capture more light. Additionally, using a tripod can help stabilize the phone for clearer shots.