This feature in the app requires a subscription

The sun and moon data in the app is retrieved from timeanddate.com. Most might think that sunrise, sunset, moonrise, moonset, and moon illumination are not important in chasing the aurora. For the most part, moon data is not a critical piece to the chase. The main takeaways you should have from the moon data are: moonrise (will there be a moon tonight), moonset (if there is a moon, how long will it be up?), and moon illumination (how bright will the moon be?).

The most important factor here is the illumination percentage. The higher the value, the brighter the moon, and the fainter the aurora will likely appear to the naked eye. You will be able to see active aurora with a full moon. And, at times, it is amazing to see! However, if aurora activity is weak, it will appear less vibrant and may have a more grayish tone to it versus the green you can see on a clear, moonless night. If you see a high illumination percentage for the night, do not let it deter your hopes of chasing the aurora if the solar wind data indicates aurora activity. You can still see good displays!

The sun data is critical to the app for several reasons. First, it provides the ability to alert users when conditions become favorable for aurora activity. Aurora activity can be visible after sunset, typically after astronomical twilight begins and will become faint to non-visible just before sunrise when astronomical twilight ends. Thus, the app uses these times to trigger updates to the probability block on the main solar wind screen. The second important aspect of the sun data is the antemeridian time for the user’s location. This is the time when the Sun is 180 degrees opposite of the user’s location. Typically, aurora activity will be the strongest, when solar data is not in a dynamic state, roughly two hours either side of this time. For example, if your location’s antemeridian for the Sun is 1am, your generalized best viewing times for aurora activity would be 11pm to 3am. Using this time will maximize your chances of seeing aurora activity when solar wind values indicate aurora is possible at your location.