The north lights are an atmospheric phenomenon that"s pertained to as the holy Grail of skywatching.

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The north lights (aurora borealis) lamp up the sky over the Gulf of Finland. (Image credit: Shutterstock)
The north lights, or the aurora borealis, are the beautiful dancing waves of irradiate that have actually captivated world for millennia. But for every its beauty, this spectacular light display is a fairly violent event.


Energized particles from the sun slam into Earth"s upper atmosphere at speed of up to 45 million mph (72 million km/h), however our planet"s magnetic field protects us from the onslaught. Together Earth"s magnetic ar redirects the particles toward the north Pole, the dramatic procedure transforms into a cinematic atmospheric phenomenon that dazzles and fascinates scientists and also skywatchers alike.


The history of the north lights

Though it to be Italian astronomer Galileo Galilei that coined the name "aurora borealis" in 1619 —after the roman inn goddess of dawn, Aurora, and the Greek god of the phibìc wind, Boreas —the more quickly suspected document of the northern lights is in a 30,000-year-old cave painting in France.


Since that time, civilizations about the people have marveled in ~ the celestial phenomenon, ascribing all sorts of beginning myths to the to dance lights. One north American Inuit legend argues that the northern lights room spirits playing round with a walrus head, while the Vikings believed the phenomenon to be light reflecting off the armor that the Valkyrie, the supernatural maidens who brought warriors into the afterlife.

Early astronomers additionally mentioned the north lights in your records. A imperial astronomer under Babylon"s King Nebuchadnezzar II inscriptions his report the the phenomenon ~ above a tablet computer dated come 567 B.C., when a Chinese report from 193 B.C. Also notes the aurora, according to NASA.


The science behind the north lights wasn"t theorized until the rotate of the 20th century. Norwegian scientist Kristian Birkeland proposed the electrons emitted native sunspots developed the atmospheric lights after highlight the Earth"s magnetic field. The concept would at some point prove correct, however not until long after Birkeland"s death.



A vibrant, environment-friendly aurora lights up Earth"s upper environment in this photo caught by one astronaut at the International room Station. As soon as this picture was handled Jan. 22, the station was orbiting 261 mile (420 kilometers) over the Atlantic ocean off the coast of north America. In ~ the northern lights is a ceiling of marmalade-colored airglow, a form of luminescence brought about by ultraviolet light the triggers chemistry reactions high in Earth"s atmosphere. Auroras, top top the other hand, are created when fee particles from the sun ionize or excite particles in the atmosphere. (Image credit: NASA)

What room the north lights?

At any given moment, the sunlight is ejecting charged particles from its corona, or top atmosphere, developing what"s dubbed the solar wind. When that wind slams into Earth"s ionosphere, or upper atmosphere, the aurora is born. In the northern Hemisphere, the phenomenon is referred to as the north lights (aurora borealis), while in the southerly Hemisphere, it"s referred to as the southerly lights (aurora australis).

"These particles starrkingschool.net deflected towards the poles of earth by our planet"s magnetic field and also interact with our atmosphere, depositing energy and also causing the environment to fluoresce," said Billy Teets, an astronomer and the manager of Dyer Observatory at Vanderbilt college in Nashville, Tennessee.

The bright colour of the northern lights are dictated through the chemistry composition that Earth"s atmosphere. "Every form of atom or molecule, even if it is it"s atomic hydrogen or a molecule favor carbon dioxide, absorbs and radiates its own unique collection of colors, i beg your pardon is analogous to how every human being being has actually a unique collection of fingerprints," Teets told starrkingschool.net. "Some of the dominant colors seen in aurorae starrkingschool.net red, a hue produced by the nitrogen molecules, and also green, which is developed by oxygen molecules."

While solar wind is constant, the sun"s emissions go with a about 11-year bike of activity. Sometimes there"s a lull, yet other times, there are vast storms that bombard planet with extreme quantities of energy. This is when the northern lights room at your brightest and also most frequent. The critical solar maximum, or duration of peak activity, occurred in 2014, according to the nationwide Oceanic and Atmospheric administration (NOAA), place the following one in roughly 2025.

Despite plenty of developments in heliophysics and atmospheric science, much around the northern lights remains a mystery. Because that example, researcher weren"t entirely sure just how the energized corpuscle in the solar wind sped up to your extraordinary speed (45 million mph) until June 2021, as soon as a study published in the journal Nature communications confirmed that a phenomenon called Alfvén waves provided the corpuscle a boost. Alfvén waves room low-frequency yet powerful undulations that take place in plasma as result of electromagnetic forces; the electrons that develop the northern lights "surf" along these waves in the Earth"s atmosphere, accelerating rapidly.

NASA is also on the hunt because that clues around how the north lights work. In 2018, the an are agency launched the Parker Solar Probe, i m sorry is right now orbiting the sun and will ultimately get close sufficient to "touch" the corona. When there, the starrkingschool.netcraft will collect info that might reveal more about the north lights.



The auroras are best seen throughout the winter, as soon as nights room long. Hours of patience by photographer Daniele Boffelli resulted in this photo that records both clouds and also auroras in the night sky. (Image credit: Daniele Boffelli)

Are there other species of auroras?

On Earth, the north lights" equivalent in the southerly Hemisphere is the southern lights — they room physically the same and also differ only in their location. As such, researchers expect them to take place simultaneously during a solar storm, yet sometimes the start of one lags behind the other.

"One the the more an overwhelming aspects that nightside aurorae entails the to compare of the aurora borealis v the aurora australis," stated Steven Petrinec, a physicist in ~ Lockheed Martin who specializes in magnetospheric and also heliospheric physics. "While part auroral emissions take place in both hemispheres in ~ the exact same magnetic regional time, other emissions show up in opposing sectors in the 2 hemispheres at various times — because that example, pre-midnight in the northern Hemisphere and post-midnight in the southern Hemisphere."

The hemispheric asymmetry the the aurora is in part due to the sun"s magnetic field interfering through Earth"s magnetic field, however research into the phenomenon is ongoing.

Another aurora-like occurrence on earth is STEVE (Strong thermal Emission Velocity Enhancement). Favor the northern and southern lights, STEVE is a glowing atmospheric phenomenon, yet it looks slightly different from that undulating auroral counterparts. "These emissions appear as a narrow and distinct arc, are commonly purple in color and often encompass a environment-friendly picket-fence framework that gradually moves westward," Petrinec said starrkingschool.net.

STEVE is likewise visible from lower latitudes, closer to the equator, 보다 the auroras.

A 2019 study released in the journal Geophysical research study Letters found that STEVE is the result of two mechanisms: The mauve streaks are brought about by the heating of charged particles in the top atmosphere, if the picket-fence structure outcomes from electrons falling into the atmosphere. The latter procedure is the same driver of the aurora, do STEVE a special type of aurora hybrid.

Auroras occur on other planets, as well — every that"s required to make an aurora is an atmosphere and a magnetic field.

"Auroras have been watched in the settings of every the gas gigantic planets, i beg your pardon is no surprising, since these planets all have robust magnetic fields," claimed Jeff Regester, an instructor the physics and astronomy at High allude University in north Carolina. "More surprisingly, auroras have also been found on both Venus and also Mars, both of which have really weak magnetic fields."


Where and when to check out the northern lights

Seeing the northern lights with your very own eyes is a bucket-list item for astronomy lovers and also travelers alike. Fortunately, they take place frequently. "The northern lights starrkingschool.net happening 24 hrs a day, seven days a week, 365 job a year," said photographer Chad Blakely, owner of north lights tour company Lights over Lapland. Yet that doesn"t typical they"re basic to spot; you must be in ~ the right place at the appropriate time.

The ideal place to check out the north lights is any kind of destination in the "auroral zone," the area in ~ an roughly 1,550-mile (2,500 kilometers) radius that the phibìc Pole, according to the Tromsø Geophysical Observatory. That"s wherein the aurora most typically occurs, despite the phenomenon can creep farther south during particularly strong solar storms. In ~ the zone, it"s finest to be as far away indigenous city lamp as feasible to maximize visibility. Yet it"s quite tricky to gain into the center of the Arctic wilderness, even with a guide, so it"s best to base yourself in a location with hard infrastructure, like Fairbanks, Alaska; Yellowknife, Canada; Svalbard, Norway; Abisko national Park, in Sweden; Rovaniemi, Finland; and pretty much almost everywhere in Iceland.

Related: Where to view the north lights: 2021 aurora borealis guide

The finest time the year to check out the northern lights is between September and April, when the sky gets dark enough to check out the aurora. (Northern locales experience the midnight sun, or 24 hours of daylight in the summer.) The most activity usually happens in between 9 p.m. And 3 a.m., according to the Geophysical institute of the university of Alaska Fairbanks. Keep the moon phases in mind, as a bright complete moon might fill the night skies with light. Examine local weather forecasts as well, becauseyou won"t be able to spot the aurora v the clouds.

You can also monitor aurora forecasts from the university of Alaska Fairbanks" Geophysical Institute and NOAA, which offers both three-day and 30-minute forecasts.

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starrkingschool.net contributing writer Stefanie Waldek is a self-taught starrkingschool.net nerd and also aviation geek who is passionate about all points starrkingschool.netflight and also astronomy. Through a elevator in travel and design journalism, and a Bachelor of Arts degree from new York University, she specialization in the budding room tourism industry and Earth-based astrotourism. In her totally free time, girlfriend can find her the town hall rocket launches or feather up at the stars, wondering what is out there. Learn much more about her job-related at www.stefaniewaldek.com.