Another geomagnetic storm means another chance for some lucky Americans to witness the northern lights this week after the second largest solar flare of the current cycle was observed Tuesday.
The colorful phenomena known as the aurora borealis is expected to be visible in some areas Thursday night going into the weekend following two observed coronal mass ejections Tuesday, including the massive X7.1 solar flare, according to the National Oceanic and Atmospheric Administration's Space Weather Prediction Center.
The center issued geomagnetic storm watches spanning minor, moderate and strong levels, and forecasted the northern lights will be present in the sky.
Last week, the center forecasted the aurora would be visible across the northwestern U.S. and some midwestern states as the display of greenish and reddish hues occur more often.
In May, a powerful geomagnetic storm unleashed a spectacular views of the northern lights in U.S. areas where auroras are not often visible. The storm also led to some reports of power grid irregularities and interference with GPS signals and farming equipment.
The aurora is expected to be visible in multiple northern U.S. states Oct. 3 through Oct. 5, according to the Space Weather Prediction Center.
Sightings are forecasted along the U.S.-Canada border, but also as far south as Oregon to Pennsylvania, according to the center. The best time to view the auroras will be on Friday, Oct. 4 from around midnight local time going into the early hours of Saturday, Oct. 5.
The center said outside variables could impact the reliability of the forecast including the precise trajectory of the solar eruption, which can change during its 93 million mile journey to Earth.
"This forecast comes with a fair amount of uncertainty because initial space weather predictions rely on remote and limited solar observations," the center said in a statement to USA TODAY Wednesday. "Auroras can be unpredictable, waxing and waning quickly. Visibility might range from bright and relatively high in the sky to faint and low on the Northern Horizon (maybe only visible with long-exposure camera shots), or even not visible at all."
People across Earth can expect more frequent and brighter northern lights to grace the sky as the sun nears the height of its 11-year cycle, making electromagnetic activity a more common occurrence.
NASA said the sun is expected to reach the peak of Solar Cycle 25 in 2025.
By then sunspots located in regions of intense magnetic activity should increase, according to the NOAA. When that magnetic activity is released, it creates intense bursts of radiation resulting in solar flares – considered by NASA to be our solar system's largest explosive events.
Solar flares emit radiation commonly in the form of ultraviolet light and X-rays that can hurtle toward Earth at the speed of light. Some of these flares can be accompanied by coronal mass ejections, or clouds of plasma and charged particles, that emerge from the sun's outermost atmosphere, the corona.
These ejections can collide with Earth’s magnetosphere, the barrier protecting humanity from the harshest impacts of space weather, to produce geomagnetic storms.
The auroras are a natural light display in Earth's sky that are famously best seen in high-latitude regions of the northern and southern hemispheres.
The phenomenon is caused when electrically charged particles from space enter Earth's atmosphere and collide with molecules and gasses like oxygen and nitrogen, causing the atmospheric particles to gain energy. To return to their normal state, the particles release that energy in the form of light, according to the University of Alaska at Fairbanks, Geophysical Institute website, which tracks the phenomenon.
As auroras form, Earth's magnetic field redirects the particles toward the poles through a process that produces a stunning display of rays, spirals and flickers that has fascinated humans for millennia. Whether hues of green, red, blue and pink dance about in the sky is due to the altitude in which the collisions occur, as well as the composition and density of the atmosphere at the time.
The auroras are best seen around the magnetic poles of the northern and southern hemispheres in places like Europe, Asia and North America. In the U.S., Alaska is well known to have the best viewing opportunities for the northern lights.
Even though conditions are prime for more impending aurora shows, experts have long struggled to accurately forecast exactly when and where the phenomenon will ever occur. Even the best predictions can only accurately be made a few days or even hours in advance.
And if it looks like the northern lights will flare up near you, it's advised to get away from cities and travel to dark locations free from light pollution. If the weather is clear, the best aurora is usually visible within an hour or two of midnight, according to NOAA.
NOAA, however, does maintain an aurora dashboard that should help skygazers track the phenomenon.
The northern lights can appear in Iceland during the day and night throughout the year, however it's best recommended to go skygazing a few hours before midnight, according to Visit Iceland.
The best time of the year to observe the auroras is between September to April, the travel guide reported.
Northern lights can be safely viewed without a telescope or microscope. The visibility of the aurora depends on multiple factors from location, weather, time of night and the level of geomagnetic activity presenting.
Anthony Robledo covers breaking and trending news for USA TODAY. Reach him at [email protected]
Eric Lagatta covers breaking and trending news for USA TODAY. Reach him at [email protected]
