What are the Northern Lights?

The Northern Lights, also known as the Aurora Borealis, is a natural light display in the Earth's sky. It is caused by the collision of charged particles from the Sun with the Earth's atmosphere.

The science behind the Northern Lights involves the interaction between the Earth's magnetic field, the solar wind, and charged particles in the Earth's upper atmosphere. The Sun continuously emits a stream of charged particles, known as the solar wind. These particles are directed towards the Earth by the Sun's magnetic field.

When the charged particles from the solar wind enter the Earth's atmosphere, they collide with gas molecules, causing them to become excited. As these excited particles return to their normal state, they emit light of various colors, creating the spectacular display of the Northern Lights.

The color of the Northern Lights depends on the type of gas particles that the charged particles collide with. Oxygen molecules produce green and red light, while nitrogen molecules produce blue and purple light.

Scientists study the Northern Lights to understand the Earth's magnetic field, the behavior of the Sun, and the interaction between the two. Studying the Northern Lights can also help us understand the effects of space weather on Earth's atmosphere, communication systems, and power grids.

 

How can I know when the Northern lights will occur?

The biggest trick to any astronomical observation is knowing when and where. Just like finding the milky way (see how here), the northern lights are easy to find given the right conditions.

First, you will want to find a spot with not too much light pollution. These days there is a lot of light pollution but do not give up! Often looking out over a lake or farm field, you can find a dark enough sky to see celestial objects. Make sure you look for these spots BEFORE the astronomical events happens. It is really hard to find places in the dark when you are not familiar with where you are going!

 

There are many, many websites and apps to identify dark places. My favorite is the website clear dark sky (https://www.cleardarksky.com/csk/) because I can look by state, site or map and there is a 3 day forecast. Go to find a chart on the left when on the website. You are looking for a picture with the forecast like the one below.

 

Second, you will want to know the phase of the moon and when is rises and sets. There are many apps for this purpose. My favorite is photopills app. They have widgets for the iphone that allow you to check sunrise, sunset, moon rise and set and milky way rise and set. I also use the apps deluxe moon, sol and sky guide, to figure out when it will be darkest. It is not an absolute requirement to have a new moon but it helps make the aurora pop.

Third, what will the weather forecast be? Before you tumble out of bed and head out, you want to know the clouds will not kill the night. I LOVE windy.com either on the desktop or app. This site gives the current cloud cover as well as the predicted cloud cover over a course of days. It is also excellent to determine when there will be great sunsets, a different blog post. Make sure to select clouds on the right. 

Finally, when will the northern lights occur? As mentioned earlier, the northern lights are caused by solar storms. Lucky for us, there are several satellites whose goal is to detect and warn of solar storms that may damage satellites or disrupt the power grid. This data is available through our very own NOAA (National Oceanic and Atmospheric Administration). However, I like the website and app spaceweather.com or the app My Aurora Forecast. When is Iceland, vedur.is is also good.

The solar activity cycle, also known as the solar cycle, is a periodic variation in the Sun's magnetic activity that repeats approximately every 11 years. Peak activity for this solar cycle will be July 2025. The solar cycle is characterized by the number of sunspots visible on the Sun's surface, as well as changes in the Sun's magnetic field.

The Kp index is a measurement of geomagnetic activity that is used to predict the occurrence of auroras, including the northern lights (also known as the Aurora Borealis). The index ranges from 0 to 9, with 0 indicating very low activity and 9 indicating extreme activity.

The Kp index is based on measurements of the strength and direction of the Earth's magnetic field at various locations around the globe. Specifically, it measures the deviation of the horizontal component of the magnetic field from its expected value. When the deviation is large, it indicates that there is a disturbance in the magnetic field, which can be caused by the interaction of the Earth's magnetic field with the solar wind.

When the Kp index is high, it indicates that there is a greater likelihood of auroral activity. Typically, a Kp index of 5 or above is required for auroras to be visible at mid-latitudes, while a Kp index of 7 or above is required for them to be visible at lower latitudes.

To use the Kp index to predict northern lights, you can monitor the Kp index on a real-time monitoring website or app, such as the NOAA Space Weather Prediction Center website. When the Kp index is high, it is a good indication that auroras may be visible in the coming hours. Space Weather also give many other indicators including solar wind speed, density, interplanetary magnetic field and, Bz. If the Bz is South (red line on the bottom half), there is a very good possibility the aurora will be visible. Bz indicates the orientation of the interplanetary magnetic field (IMF). If the Bz is positive (northward), then the earth's magnetic field will block most of the solar wind, and geomagnetic storming is unlikely. This is the most common reason one would not see a great show despite a solar event.

In a nutshell, Kp7 and higher is what most of us can see really well in the united states unless you are close to the Canadian border or farer north. If you are somewhere farther north, Kp3 and high you can see the aurora. As you can see, there is at least a three day predictive window and a real time estimate of aurora coverage. You can even set you space weather app to give you alerts on your lock screen when solar activity indicates the potential of an aurora!

Big solar storms are usually detectable about 15 days in advance. Thus, if you are flexible about your travel dates, check the north lights forecast, particularly in the darkest months of the year.

 

What am I looking for and where do I look for the Northern lights?

Naturally you will want to look north, over dark flat area. If at all possible identify a foreground object like a rock, barn, person, tree etc to provide depth. To the naked eye, in a good dark place, the northern lights will look greyish green. With a Kp 4-5 you may see a faint aurora on the horizon in the Upper peninsula of Michigan for example, a Kp6 and above you will see quick dancing lights that will fill the sky. Patience is a virtue. Be prepared to spend the night from rough 11 pm til dawn, waiting for the show to begin. Once it does don’t quit until it does! If you are unsure if the aurora is occurring, bust out your phone or camera and take some pictures in the northerly direction. Cameras have better light sensitivity than our eyes do.

Planning and safety

When you do go out to chase the aurora remember a few things:

1) Bring extra batteries (camera and flashlight) and a flashlight or head lamp, preferable with a red light so yu don't ruin your night vision

2) Warm clothes, blankets and footwear, you can get cold fast

3) Food and water! Warm if possible

 

Can I use my phone to shoot the northern lights?

Yes, the most critical thing to have in had whether you are using a camera or a phone is a tripod. This will eliminate the shake of your hand. Also make sure you are shooting in RAW format if possible, this preserves all the data. In jpeg, half the information is thrown away by the camera. You can edit your photo professionally using the app snapseed. It is free and powerful app. The idea shutter time for the northern lights is between 1-30 seconds. It is very hard to hold your phone steady for that long.

 

There are apps that let you manually control the settings of your phone’s camera so you can achieve a 1-30 sec exposure. However, most smart phones come with a night mode of some sort. For example, all iphones from 11 and newer have this feature.

In low-light conditions Night Mode will automatically turn on. The Night Mode icon will appear in the top left corner of your phone. This feature keeps the camera sensor open for a longer amount of time in order to get more light in, and therefore capture more detail in the image. In photography, this feature is known as long exposure. The exposure time you use is the same as how long it takes for your phone to take a photo.

By default, depending on how dark the environment is, the exposure in iPhone’s Night Mode is somewhere between 1 and 3 seconds. For the Northern Lights we need more than this. We need to change the exposure time to the maximum possible:

1. There’s a hidden settings menu in the iPhone’s camera app. Open this menu using the top arrow.
2. Look for the Night mode icon and tap on it.
3. A slider will appear that allows you to adjust the exposure time.
4. Slide it all the way to the right at Max.
5. Now this Max value will represent 10 seconds if the iPhone detects movement, such as a shaky hand. If you are using a tripod, then the Max value is 30 seconds. This is the value that we need for the Aurora Borealis or Northern Lights. You will still be able to capture something at 10 seconds as well, but the quality of the image will be quite bad compared to the 30 seconds one.
6. For best quality photos with the Northern Lights aim for 30 seconds Night Mode. When luck is on your side and the Aurora is very bright, the Night Mode Max value will drop under 30 seconds, usually 27 or 22 seconds.
7. Even when using a tripod you should choose the right place to put it down. If you place the tripod with the phone on the hood of a car with the engine on it might detect vibrations and use just 10 seconds. If you have a windy night, then it might be impossible to see that 30 seconds exposure that you want.
8. Exposure Adjustment Yet another setting? Don’t worry, you might not need to use this one. Sometimes however, the light around you might be very bright, like in the winter when everything is covered with snow. Since snow reflects a lot of light, and Night Mode keeps the camera sensor open to let more light it, it is possible that your photos will be too bright. In this condition you might want to try and change the Exposure Adjustment.
9. I know it is a bit confusing because of the name: Night Mode means long exposure (the camera sensor is exposed to the light for a longer period of time to capture details in the dark) and this is Exposure Adjustment (to prevent some parts of the photo to be overexposed and lose details).
10. For Exposure Adjustment you need to open the same hidden menu using the top arrow. In this menu you will see an icon with a + and - inside a circle. Click on it and lower the exposure to a negative value. The current Exposure Adjustment value will be visible at the top of the screen, right next to Night mode. If your iPhone is set to preserve this setting, don’t forget to set it back to 0 when you don’t need it.

 

What camera settings do I use?

Photographing the Northern Lights can be a magical experience and with the right preparation, equipment, and technique, you can capture stunning images of this natural wonder. Here are some tips on how to photograph the Northern Lights:

1. Use a sturdy tripod: To avoid camera shake, it's important to use a sturdy tripod. Make sure it's stable and can support the weight of your camera and lens.
2. Use a wide-angle lens: A wide-angle lens will allow you to capture more of the Northern Lights in your frame. A fast lens with a wide aperture (f2.8 – f1.8) will allow you to gather more light and capture sharper images. I have used my 24-105 mm f4.0 and sstill gotten nice images.
3. Set your camera to manual mode: In manual mode, you have more control over your camera's settings. Set your ISO to a high value (between 800 and 3200) to capture more light. Set your shutter speed to between 1 and 30 seconds, depending on the brightness of the Northern Lights. Use a remote or timer to avoid camera shake. Your camera’s 2 sec delay is great for this. I usually start at 5 sec and an ISO of 1600
4. Shoot in Raw format. RAW format preserves all of the data the camera takes in. When shooting in jpeg (which can be the default setting)
5. Focus. Switch your camera to manual focus. You’ll need to lock your camera to focus to the farthest distance it can focus to, infinity. The infinity point is usually marked on the lens, though be aware that the marker isn’t always totally accurate. Manually find infinity focus each time I go to shoot the northern lights, by finding some distant lights to point my camera at, and then I turn on live view and zoom my screen (not the lens) in on the lights. Then I manually adjust my lens so that it focuses on the lights. It’s focused when the dots become as small as possible. If you have a Sony camera, turn on peak focusing. As you are using this, the camera will show colored dots showing when it is in focus.
6. Practice and experiment: Practice makes perfect, so keep experimenting with your camera settings and techniques to improve your Northern Lights photography skills. As the light show goes on. Keep checking your photo and histogram to make sure you are capturing all the possible light!

Remember, the Northern Lights are a natural phenomenon, and there's no guarantee that you'll see them on any given night. However, with the right preparation and a bit of luck, you can capture stunning images of this awe-inspiring spectacle.