The last time the aurora borealis graced the skies of the US was back in May, when nearly half the country could see the scenic northern lights, with some areas enjoying the view for almost a week straight. If you missed that event, get your cameras ready. Another solar outburst is on its way toward Earth, and it'll cause the breathtaking aurora borealis to appear on Wednesday night as far south as New York and Idaho.
How do we know? On July 21, the National Oceanic and Atmospheric Administration reported a coronal mass ejection from the sun. A coronal mass ejection is essentially a break in the sun's magnetic field, which causes an explosion that launches solar particles into space. Those solar particles are now are on their way to Earth, where they can cause a geomagnetic storm.
The stunning natural light show that we call the aurora borealis is caused by such storms, NASA says, when "energetic charged particles from these events are carried from the Sun by the solar wind."
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Those particles are set to arrive at Earth on the evening of July 24. Once they get here, they may cause a geomagnetic storm that'll cause auroras to be visible further south than they usually are. According to NOAA, the aurora borealis may become visible over some northern and upper Midwest states from New York to Idaho. NOAA isn't specific as to which states will see it, but Minnesota, North Dakota, Montana, Michigan and Wisconsin are pretty safe bets. It may extend further south into neighboring states as well.
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In case you were curious about what a coronal mass ejection might look like, you can see footage of this particular CME at SpaceWeather.com. The short video, also posted on Reddit, shows the initial explosion on the left side before it erupts around the entire sun. These types of CMEs are commonly called full-halo CMEs, where the explosion exits the sun in a ring that goes all the way around.
According to NOAA, the evening of July 24 will be your only opportunity for this particular aurora event. The agency also says this isn't a particularly strong event, rating it at a G2 level. A G2-rated geomagnetic storm is considered "moderate," which is the second lowest rating NOAA provides. Outside of some high-voltage alarms going off in high-altitude power systems, there isn't expected to be any damage, and this event isn't harmful to humans at all.
For the sake of comparison, the May event that brought the auroras down as far south as San Francisco was rated a G5 storm and it causedquite a number of electrical disturbances over the span of several days. In 2022, a similar G3 storm pushed the auroras as far south as Pennsylvania and Oregon.
How to see the aurora borealis
Does it seem like you can never see a hyped aurora where you live? Bill Murtagh, program coordinator at NOAA's Space Weather Prediction Center, talked to CNET about this very issue back in 2022. Murtagh compared it to a popular outdoor hobby that also takes a lot of patience: fishing.
"You might be out hunting it for hours on end," he told me, "and then the perfect storm of events comes along, and you finally see it."
Read more: Why Can I Never See The Northern Lights From Where I Live?
There's also no specific time of night that's best to get out and photograph the aurora borealis. You want it to be dark, but that's about as specific as predictions can get.
City dwellers are at a disadvantage because of light pollution, which is pretty much exactly what it sounds like: the brightening of the night sky in the city, caused by streetlights and other sources. That inhibits our ability to see stars and planets. And visibility could be tougher this week for people who live surrounded by the lights of a city or even a suburb, since the storm is only rated a G2.
But say you get in the car and drive out of your city or suburb to a rural area with no streetlights. There's another element that's out of your control: the weather. Cloudy conditions can roll over any state at any time, making aurora sightings even tougher to predict.
Many people travel to Alaska or northern countries just in the hope of seeing, and photographing, an aurora. Murtagh recommended Anchorage, Fairbanks and Yukon, Alaska; Helsinki; and northern Scandinavia. There are even trip planners now who organize tours around potentially seeing the aurora.