The equinox might fuel powerful Northern Lights by creating 'holes' in Earth's magnetic field
- March 2024 may be the best month in the best year to see the Northern Lights, aka aurora borealis.
- That's because the sun is hyperactive, and the equinox can create holes in Earth's magnetic field.
This could be the best month, of the best year for two decades, to see the Northern Lights, in part, thanks to openings in Earth's magnetic field.
The aurora borealis, commonly called the Northern Lights, are the stunning ribbons of shimmering green, pink, purple, and red that dance in the skies of the Arctic.
When conditions are just right, they can appear as far south as Arizona or even Florida.
If you're lucky and you plan right, you might be able to see the Northern Lights this month. This all applies to the aurora australis (the Southern Lights) as well, in places like Australia and New Zealand.
Why the sun and holes in our magnetic field make good auroras now
The Northern Lights occur when charged particles and magnetic fields flowing out of the sun, called the solar wind, wash over Earth.
Our planet's magnetic field channels the solar wind toward the poles, where the charged solar particles interact with molecules in the atmosphere to make the colorful aurora.
Both steps of that process are ramped up right now.
For one, the sun is near the peak of its solar cycle. Powerful eruptions, solar flares, and bursts of solar wind from coronal holes in the sun's atmosphere are becoming more common, sending more winds rushing over our planet.
Secondly, once those winds reach Earth, spring and fall are the best times for them to produce a spectacular aurora. Scientists think that's because of the equinoxes.
The equinox happens when Earth's axis is perpendicular to the sun's rays. That causes a special alignment where our planet's magnetic field points in precisely the opposite direction of many of the solar wind's magnetic fields.
This alignment causes the Earth and sun's magnetic fields to merge. The process, called magnetic reconnection, creates openings in Earth's magnetic field that allow the solar wind to transfer energy to our atmosphere, and potentially cause more aurora.
Though he doesn't like the analogy, Matt Owens, a professor of space physics at the University of Reading, told Business Insider in an email that "the reconnection process could be very loosely described as making holes or cracks in the magnetosphere."
The below NASA visualization shows what our magnetic field looks like around the equinox.
Specifically, March was the most active month for auroras in a NASA study of 75 years of data. October was a close second, then April, then September.
March 2023 saw the biggest aurora event of that year, for example. At the end of the month, a series of solar activities triggered auroras so powerful that they appeared across the US, as far south as Phoenix, Arizona.
It happened quickly, though, and most people missed it.
How to see and photograph the aurora
First, check the aurora forecast on the National Oceanic and Atmospheric Administration website. If things are happening on the sun, this can change day-to-day.
When the northern lights come to lower latitudes, including most of the US, they can be fainter than they appear in photos from Alaska or Norway.
Instead of this…
… you might be looking for something like this:
So if you live in a city, do your best to leave it. Find a safe spot with clear, dark skies far from city lights.
Prepare for cold weather with blankets and hot beverages. You may have used your phone or looked at screens to get you where you need to go, so be patient, and let your eyes adjust to the darkness.
If you can't leave the city, do your best to block out its light pollution. Go to a nearby nature reserve, or the top of a hill, and try to keep the city lights out of your gaze.
Look for anything colorful and out of the ordinary. There are several different types of aurora.
You can try to snap pictures of the auroras with a camera, but make sure not to transfer it too quickly from a hot to a cold environment to avoid condensation, according to the Royal Photographic Society.Preset your camera before leaving a warmer space so your fingers don't get too cold — higher aperture may be better, but you may have to adjust your settings if the aurora is moving quickly. You can find information on how to set SLR cameras here.This could be your best chance for another decade
It's been about a decade since the last solar maximum, and when it's over the sun's activity will die down and it will be another 11 years until the next one.