The Northern Lights will be visible in the U.S. tonight. Heres how to view it.
The Northern Lights are putting on a show for Martin Luther King Jr. Day, delivering a beautiful display of light across several U.S. states. Here's how to watch the aurora borealis this week.
According to the U.S. National Oceanic and Atmospheric Administration's (NOAA) Space Weather Prediction Center (SWPC), this week's Northern Lights will be visible on Jan. 19 and linger through to the next day in some areas. Even so, you're best off catching the aurora on Monday if you're able, as it will be significantly less prominent later in the week. Those at higher latitudes will have a better chance of seeing the aurora, though the notable strength of this week's display means the Northern Lights may be visible as low as Alabama and northern California.
This wide range of visibility is because Monday's Northern Lights have been caused by the largest solar radiation storm in over 20 years, resulting in a particularly strong aurora. The SWPC has issued a severe G4 geomagnetic storm alert in response, warning that it may cause widespread problems with the power grid, and that GPS navigation and high frequency radio may also be inoperable for hours. Infrastructure operators and authorities have been notified about the expected disruptions.
Fortunately, the SWPC states that there isn't much the general public needs to do in response to the geomagnetic storm. All that's required is that you stay informed and, if weather permits, search for an aurora.
How to get the best view of the Northern Lights
The easiest way to view the Northern Lights is to simply head outside during the night and look up. Auroras can be visible from over 600 miles away in the right conditions, so it's worth checking even if you're slightly outside the predicted zone of visibility. However, if you would like to give yourself the best possible conditions for viewing an aurora, there are a few factors to keep in mind.
According to the SWPC, the best time to see the Northern Lights is between 10 p.m. and 2 a.m., as the level of geomagnetic activity increases during this period. This is also the darkest time of night, providing the strongest contrast with the bright Northern Lights to make them more visible.
Choosing a viewing area with as little light pollution as possible will also enhance your experience. A Certified Dark Sky Place close to the U.S.-Canadian border would be an optimal choice, as all of them have been assessed and recognised for having minimal light pollution. If you can't make it to one, just try to reduce light pollution where you are.
What causes the Northern Lights?
While auroras take place in the Earth's atmosphere, they are actually the result of solar activity.
When a solar flare or coronal mass ejection occurs on the Sun's surface, large amounts of plasma and magnetic field are expelled from the outermost layer of its atmosphere. This creates a high-speed solar wind, or solar storm, which may travel through space to reach Earth. Depending upon the nature of the solar activity, the journey to Earth can take as little as a few minutes or as long as a few days.
Once the solar storm does reach Earth, most of it is reflected back out into space by Earth's magnetic field. However, not all of it is turned away. Some charged ion particles enter the magnetic field instead, then travel to Earth's polar regions where said field is weakest.
The charged ions then collide with oxygen and nitrogen atoms, creating chemical reactions which emit light: an aurora. The Northern and Southern Lights are both created in this same way. The only difference is that the aurora borealis is in the Northern Hemisphere, while the aurora australis is in the Southern Hemisphere.
