Aurora alert: You may be able to see the northern lights and the southern lights this week, as the stunning display is expected to make another strong showing.
Here’s what to know:
Where and when are the northern lights visible?
The National Oceanic and Atmospheric Administration (NOAA) issued a geomagnetic storm watch that is in effect through August 1, which means there are multiple chances to see the aurora borealis, or northern lights, over the next few nights.
The current prediction for July 30 in the United States, according to NOAA, is a view line that extends through New York, South Dakota, and Washington State.
But for tomorrow night, July 31, the possible view line is even further south, into the northeast United States, northern Illinois, Nebraska, and Oregon.
For a full look at where they’re visible, see NOAA’s aurora dashboard here.
What causes them?
We’re currently in a period of strong solar activity because we are at or near the peak of our sun’s 11-year solar cycle. That means there are a lot of sunspots on the surface of the sun, and these produce intense solar storms. When these sunspots are pointed at Earth, there’s an increased chance of an aurora, or northern lights show, as there is right now.
Sunspots are basically the sun’s magnetic field on the visible surface of the sun, and they produce solar flares, which are violent explosions on the surface of the sun. Solar flares often are accompanied by coronal mass ejections, or CMEs. These are bubbles of the sun’s magnetic field and plasma ejected from the sun’s surface and sent into the solar system. When they interact with Earth’s atmosphere, that’s what produces an aurora.
Tips for viewing the northern lights
The northern lights and southern lights are very hard to predict because scientists cannot precisely determine when a CME (or multiple CMEs, in this case) will hit Earth. NOAA does offer estimated times of solar activity, but they are very much estimates, rather than predictions. Unfortunately, it isn’t like a solar eclipse, when scientists can deliver a precise time and path. Auroras can be visible anytime after it’s dark in your location.
It’s possible the northern lights will be visible well south of the predicted view line, as occurred in May. If it’s clear where you are, you can head outside to check the sky when it’s fully dark (city lights may, as always, obscure any view of the aurora that you have).
NOAA also offers a 30-minute forecast that can be helpful.
If you’re not sure of what you’re seeing, look through a phone or camera lens, because that can make the aurora easier to spot. It’s possible you’ll just see the glow of the sky if you’re at a nontraditional latitude for the aurora, instead of the more vibrant view you’d see closer to the poles.