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{Also known as the Northern Lights}

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WHAT IS THE AURORA BOREALIS?

The Aurora is an incredible light show caused by collisions between electrically charged particles released from the sun that enter the earth's atmosphere and collide with gases such as oxygen and nitrogen. The lights are seen around the magnetic poles of the northern and southern hemispheres.

Auroras that occur in the northern hemisphere are called 'Aurora Borealis' or 'northern lights' and auroras that occur in the southern hempishere are called 'Aurora Australis' or 'southern lights'.

Both Aurora's can be seen in the northern or southern hemisphere, in an irregularly shaped oval centred over each magnetic pole. Scientists have learned that in most instances northern and southern auroras are mirror-like images that occur at the same time, with similar shapes and colours. Auroral displays can appear in many vivid colours, although green is the most common. Colours such as red, yellow, green, blue and violet are also seen occasionally. The auroras can appear in many forms, from small patches of light that appear out of nowhere to streamers, arcs, rippling curtains or shooting rays that light up the sky with an incredible glow.

WHAT CAUSES AURORAS?

Auroras are the result of collisions between gaseous particles (in the Earth's atmosphere) with charged particles (released from the sun's atmosphere). Variations in colour are due to the type of gas particles that are colliding. The most common aurora colour which is green, is produced by oxygen molecules located about 60 miles above the earth. The rarer red auroras are produced by high-altitude oxygen, at heights of up to 200 miles. Nitrogen produces blue or purple aurora.

How do charged particles from the sun get here?

Generally, it is when there is an opening in the suns atmosphere that allows electrons and protons to flow out. In terms of auroras, we need quite a lot of charged particles colliding with earth's atmosphere to create vivid displays, so this usually requires quite a large opening, such as a coronal hole, or a sunspot. The connection between Auroras and sunspot activity has been suspected since about 1880. Thanks to research conducted since the 1950′s, we now know that electrons and protons from the sun are blown towards the earth on the 'solar wind'.

When the charged particles are blown towards the earth by the solar wind, they are largely deflected by the earth's magnetic field. However, the earth's magnetic field is weaker at either pole and therefore some particles enter earth's atmosphere and collide with gas particles. These collisions emit light that we perceive as the dancing lights of Auroras.

The lights of the Aurora generally extend from 80 kilometres (50 miles) to as high as 640 kilometres (400 miles) above the earth's surface.

WHERE IS THE BEST PLACE TO WATCH AURORA?

Because the phenomena occurs near the magnetic poles, getting as close to these poles as possible will rapidly increase the chances of viewing aurora. As the magnetic south pole is in Antarctica, unless your a scientist working there, it usually leaves the northern hemisphere the most sensible option of viewing aurora. It should be mentioned however that during strong solar storms, aurora australis are quite often visible in places south from Australia. But generally speaking, the best places to watch the aurora are usually are North America or Europe.

In North America, the north western parts of Canada, particularly the Yukon, Nunavut, Northwest Territories and Alaska are favourable. In Europe, Scandinavia, particularly the Lapland areas of Norway, Sweden and Finland is very good for aurora viewing. Iceland is also a good place for auroras and Auroral displays can also be seen over the southern tip of Greenland.

In terms of what physically makes a place good to view aurora aside from the proximity to the magnetic poles. The most important point is 'light pollution', it will ruin any aurora show, so the best places to watch the auroras should be away from light pollution. In most cases in the north this usually only requires driving for 30 minutes of a city/town and you should be in light pollution free skies.

The other most important is to be on relatively high ground with an un-obscured view north (this is not necessary if you are so far North the auroras are usually directly overhead). The further away from the north pole you are, generally speaking the lower on the horizon the aurora will be. Of course this depends on a lot of factors such as aurora strength (Kp level).

Those are really the main points to successful aurora viewing, if you get them all right, then you should be in for a good show. Of course if there are clouds, then forget all the above! Auroras are not visible through most types clouds.

The following graphic shows what strength Kp is needed to view aurora where you are. For the current Kp strength, check our forecast page:

WHEN IS THE BEST TIME TO WATCH FOR AURORAL DISPLAYS?

Whenever there is a significant event on the sun and it is earth facing, it usually means a great aurora show is in the offing. There are times when the sun is very quiet and there are times when it is very active. This is known as the solar cycle. The solar cycle is 11 years. It has a solar minimum period and a solar maximum period, it is the solar maximum period when it is at it's most active. The next peak period aka solar max is late 2013.

Winter in the north is generally a good season to view lights. The long periods of darkness and the frequency of clear nights provide many good opportunities to watch the auroral displays. Usually the best time of night (on clear nights) to watch for auroral displays is between 10pm to 2am. Although they can, and quite often are, seen either side of these times.

Some great videos:

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What is the Aurora Borealis? - Aurora Service (Europe)

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The Aurora is an incredible light show caused by collisions between electrically charged particles released from the sun that enter the earth's atmosphere and collide with gases such as oxygen and nitrogen. The lights are seen around the magnetic poles of the northern and southern hemispheres.

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The aurora borealis - otherwise known as the northern lights - is a vivid demonstration of the Earth's magnetic field interacting with charged particles from the sun. It's also beautiful, and worth braving a cold night out when visiting the high northern (or southern) latitudes.

Auroras are centered on the Earth's magnetic poles, visible in a roughly circular region around them. Since the magnetic and geographic poles aren't the same, sometimes the auroras are visible farther south than one might expect, while in other places it's farther north. [ Aurora Photos: Northern Lights Dazzle in Night-Sky Images]

In the Northern Hemisphere, the auroral zone runs along the northern coast of Siberia, Scandinavia, Iceland, the southern tip of Greenland and northern Canada and Alaska. Auroras are visible south of the zone, but they are less likely to occur the farther away you go. The Southern Hemisphere auroral zone is mostly over Antarctica, or the Southern Ocean. To see the southern lights (or aurora australis), you have to go to Tasmania, and there are occasional sightings in southern Argentina or the Falklands - but those are rare. Here are some dazzling facts about these light shows.
1. Different ions make different colors

(Image credit: Image copyright Mike Taylor - Taylor Photography)

Aurora displays are created when protons and electrons stream out from the solar surface and slam into the Earth's magnetic field. Since the particles are charged they move in spirals along the magnetic field lines, the protons in one direction and the electrons in the other. Those particles in turn hit the atmosphere. Since they follow the magnetic field lines, most of them enter the atmospheric gases in a ring around the magnetic poles, where the magnetic field lines come together.

The air is made up largely of nitrogen and oxygen atoms, with oxygen becoming a bigger component at the altitudes auroras happen - starting about 60 miles up and going all the way up to 600 miles. When the charged particles hit them, they gain energy. Eventually they relax, giving up the energy and releasing photons of specific wavelengths. Oxygen atoms emit green and sometimes red light, while nitrogen is more orange or red.
2. They are visible from space

(Image credit: NASA)

Satellites can take pictures of the aurora from Earth's orbit - and the images they get are pretty striking. In fact, auroras are bright enough that they show up strongly on the nightside of the Earth even if one were looking at them from another planet.

The International Space Station's orbit is inclined enough that it even plows through the heavenly lights. Most of the time nobody notices, as the density of charged particles is so low. Rodney Viereck, director of the Space Weather Prediction Test Bed at the National Oceanic and Atmospheric Administration (NOAA),said the only time it matters is during particularly intense solar storms, when radiation levels are high. At that point all the astronauts have to do is move to a more protected area of the station. (Ironically, intense solar storms can actually reduce the amount of radiation around the space station, because of the interactions of charged particles with the Earth's magnetic field). Meanwhile, ISS astronauts can snap gorgeous auroral panoramas.
3. Other planets have them

(Image credit: X-ray: NASA/CXC/SwRI/R.Gladstone et al.; Optical: NASA/ESA/Hubble Heritage (AURA/STScI))

Voyagers 1 and 2 were the first probes to bring back pictures of auroras on Jupiter and Saturn, and later Uranus and Neptune. Since then, the Hubble Space Telescope has taken pictures of them as well. Auroras on either Jupiter or Saturn are much larger and more powerful than on Earth, because those planets' magnetic fields are orders of magnitude more intense.

On Uranus, auroras get weirder, because the planet's magnetic field is oriented roughly vertically, but the planet rotates on its side. That means instead of the bright rings you see on other worlds, Uranus' auroras look more like single bright spots, at least when spied by the Hubble Space Telescope in 2011. But it's not clear that's always the case, because no spacecraft has seen the planet up-close since 1986.
4. The lights can move south
Occasionally the auroras are visible farther from the poles than usual. In times of high solar activity, the southern limit for seeing auroras can go as far south as Oklahoma and Atlanta - as it did in October 2011. A record was probably set at the Battle of Fredericksburg in Virginia in 1862, during the Civil War, when the northern lights appeared. Many soldiers noted it in their diaries. Viereck said it is actually harder now than a century ago to tell when auroras are very bright, because so many Americans live in cities, and the lights wash out the aurora. "You could have a major auroral storm in New York City and if you looked up you wouldn't notice," he said.
5. Divine signs?

(Image credit: NASA)

Speaking of that Civil War aurora, a few observers took the swirling light show as a bad omen (notably Elizabeth Lyle Saxon, who wrote about the phenomenon in her 1905 book, "A Southern Woman's War Time Reminiscences"), though most people just saw it as an unusual and impressive display. In areas where the lights are rare, they were often taken as bad omens, as the ancient Greeks did. The Inuit, who see auroras more often, thought the lights were spirits playing in the sky, and some groups would tell children not to play outside at night lest the aurora disappear and take them along. Lapplanders thought the lights were the spirits of the dead. In the Southern Hemisphere, the Maori and Aboriginal people of Australia associated the southern lights with fires in the spirit world.

Oddly, the Old Norse and Icelandic literature doesn't seem to mention auroras much. The Vikings thought the displays might be fires that surrounded the edge of the world, an emanation of flame from the northern ice, or reflections from the sun as it went around the other side of the Earth. All three ideas were considered rational, non-supernatural explanations in the Medieval Period.
6. Cold fire
The northern lights look like fire, but they wouldn't feel like one. Even though the temperature of the upper atmosphere can reach thousands of degrees Fahrenheit, the heat is based on the average speed of the molecules. After all, that's what temperature is. But feeling heat is another matter - the density of the air is so low at 60 miles (96 kilometers) up that a thermometer would register temperatures far below zero where aurora displays occur.
7. Cameras see it better
Auroras are relatively dim, and the redder light is often at the limit of what human retinas can pick up. Cameras, though, are often more sensitive, and with a long-exposure setting and a clear dark sky you can pick up some spectacular shots.
8. You can't predict a show
One of the most difficult problems in solar physics is knowing the shape of a magnetic field in a coronal mass ejection (CME), which is basically a huge blob of charged particles ejected from the sun. Such CMEs have their own magnetic fields. The problem is, it is nigh impossible to tell in what direction the CME field is pointing until it hits. A hit creates either a spectacular magnetic storm and dazzling aurora with it, or a fizzle. Currently there's no way to know ahead of time.

NOAA has an online map that can tell you what auroral activity looks like on any given day, showing the extent of the "auroral oval" and where one is more likely to catch the lights.

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Northern Lights: 8 Dazzling Facts About Auroras

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The aurora borealis - otherwise known as the northern lights - is a vivid demonstration of the Earth's magnetic field interacting with charged particles from the sun. It's also beautiful, and worth braving a cold night out when visiting the high northern (or southern) latitudes.

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What are Northern Lights?

The bright dancing lights of the aurora are actually collisions between electrically charged particles from the sun that enter the earth's atmosphere. The lights are seen above the magnetic poles of the northern and southern hemispheres. They are known as 'Aurora borealis' in the north and 'Aurora australis' in the south..
Auroral displays appear in many colours although pale green and pink are the most common. Shades of red, yellow, green, blue, and violet have been reported. The lights appear in many forms from patches or scattered clouds of light to streamers, arcs, rippling curtains or shooting rays that light up the sky with an eerie glow.

What causes the Northern Lights?

The Northern Lights are actually the result of collisions between gaseous particles in the Earth's atmosphere with charged particles released from the sun's atmosphere. Variations in colour are due to the type of gas particles that are colliding. The most common auroral color, a pale yellowish-green, is produced by oxygen molecules located about 60 miles above the earth. Rare, all-red auroras are produced by high-altitude oxygen, at heights of up to 200 miles. Nitrogen produces blue or purplish-red aurora.

The connection between the Northern Lights and sunspot activity has been suspected since about 1880. Thanks to research conducted since the 1950's, we now know that electrons and protons from the sun are blown towards the earth on the 'solar wind'. (Note: 1957-58 was International Geophysical Year and the atmosphere was studied extensively with balloons, radar, rockets and satellites. Rocket research is still conducted by scientists at Poker Flats, a facility under the direction of the University of Alaska at Fairbanks - see web page http://www.gi.alaska.edu/

The temperature above the surface of the sun is millions of degrees Celsius. At this temperature, collisions between gas molecules are frequent and explosive. Free electrons and protons are thrown from the sun's atmosphere by the rotation of the sun and escape through holes in the magnetic field. Blown towards the earth by the solar wind, the charged particles are largely deflected by the earth's magnetic field. However, the earth's magnetic field is weaker at either pole and therefore some particles enter the earth's atmosphere and collide with gas particles. These collisions emit light that we perceive as the dancing lights of the north (and the south).

The lights of the Aurora generally extend from 80 kilometres (50 miles) to as high as 640 kilometres (400 miles) above the earth's surface.

Where is the best place to watch the Northern Lights?

Northern Lights can be seen in the northern or southern hemisphere, in an irregularly shaped oval centred over each magnetic pole. The lights are known as 'Aurora borealis' in the north and 'Aurora australis' in the south. Scientists have learned that in most instances northern and southern auroras are mirror-like images that occur at the same time, with similar shapes and colors.

Because the phenomena occurs near the magnetic poles, northern lights have been seen as far south as New Orleans in the western hemisphere, while similar locations in the east never experience the mysterious lights. However the best places to watch the lights (in North America) are in the northwestern parts of Canada, particularly the Yukon, Nunavut, Northwest Territories and Alaska. Auroral displays can also be seen over the southern tip of Greenland and Iceland, the northern coast of Norway and over the coastal waters north of Siberia. Southern auroras are not often seen as they are concentrated in a ring around Antarctica and the southern Indian Ocean.

Areas that are not subject to 'light pollution' are the best places to watch for the lights. Areas in the north, in smaller communities, tend to be best.

When is the best time to watch for auroral displays?

Researchers have also discovered that auroral activity is cyclic, peaking roughly every 11 years. The next peak period is 2013.
Winter in the north is generally a good season to view lights. The long periods of darkness and the frequency of clear nights provide many good opportunities to watch the auroral displays. Usually the best time of night (on clear nights) to watch for auroral displays is local midnight (adjust for differences caused by daylight savings time). http://www.gi.alaska.edu/

Legends of the Lights

'Aurora borealis', the lights of the northern hemisphere, means 'dawn of the north'. 'Aurora australis' means 'dawn of the south'. In Roman myths, Aurora was the goddess of the dawn. \par Many cultural groups have legends about the lights. In medieval times, the occurrences of auroral displays were seen as harbingers of war or famine. The Maori of New Zealand shared a belief with many northern people of Europe and North America that the lights were reflections from torches or campfires.

The Menominee Indians of Wisconsin believed that the lights indicated the location of manabai'wok (giants) who were the spirits of great hunters and fishermen. The Inuit of Alaska believed that the lights were the spirits of the animals they hunted: the seals, salmon, deer and beluga whales. Other aboriginal peoples believed that the lights were the spirits of their people.

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The bright dancing lights of the aurora are actually collisions between electrically charged particles from the sun that enter the earth's atmosphere. The lights are seen above the magnetic poles of the northern and southern hemispheres. They are known as 'Aurora borealis' in the north and 'Aurora australis' in the south..

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10 Illuminating Facts about the Northern Lights

According to Roman mythology, Aurora was the goddess of the dawn. The word "borealis," however, is Greek for "wind." The combined phrase "aurora borealis" therefore means "dawn wind," known in English as the Northern Lights. This phenomenon has fascinated peoplefor thousands of years, a fascination that clearly continues today: The northern lights are one of the major attractions of the Arctic, and indeed there are a number of Northern Lights cruises in the Arctic specifically devoted to viewing this magical lightshow.

1. The Ancients Thought the Northern Lights Were Fire

For thousands of years, no one knew exactly what the Northern Lights were or where they came from. Aristotle made the first scientific account of the lights in the 4 th century BCE, likening them to flames of burning gas. In the thirteenth century CE, the first detailed attempt at explaining the lights was made in Konungs skuggsjá, or The King's Mirror, a Norwegian educational text. The theory was that the lights were reflections from Earth's oceans. Another theory was that they were reflected sunlight coming from below the horizon, lighting up the sky. Even fires in Greenland were speculated as being the cause of these mysterious lights.

2. An Aurora in Europe Sparked Aurora Borealis Insights

In 1708, Swedish scientist Sun Arnelius suggested that solar rays were being reflected off ice particles into the atmosphere. Eight years later, a strong aurora in Europe lead to more scientific research being conducted on what cause the lights. Sir Edmund Halley published the first detailed description of the Northern Lights, suggesting that, "Auroral rays are due to particles, which are affected by the magnetic field, the rays parallel to Earth's magnetic field."

3. The Northern Lights Continuously Encircle the North Pole

In the 1800s, Christopher Hansteen set up observation stations and arranged with sea captains to record the Earth's magnetic field. Hansteen become the first person to note that the aurora occurs as a continuous ring around the geomagnetic pole. Taking this finding forward, Danish astrophysicist Sophus Tromholt organised a network of northern lights observation sites from which he discovered that the lights formed a ring around the North Pole.

4. Earth's Magnetic Field Guides the Northern Lights

At the start of the 20 th century, the Norwegian physicist Kristian Birkeland conducted an experiment in which he placed a spherical magnet inside a vacuum chamber, then shot an electron beam at it. Birkeland found that the beam was guided by the magnetic field, hitting the sphere near the poles. He then reasoned that the sun must be firing beams toward Earth, and it was Earth's magnetic field that guided them near the poles.

5. Trapped High-Energy Solar Particles Make Up the Aurora Borealis

In the 1930s, Sydney Chapman and Vincent Ferraro hypothesised that clouds of electrically charged particles fired from the sun fly across space and envelop the Earth. Further research showed that as the particles reach Earth, they go around the atmosphere. The majority of them fly past the Earth, while a few swirl back toward it and enter the atmosphere. With the dawn of the Space Age, satellite data showed that the space around Earth is filled with high-energy particles that are trapped by the Earth's magnetic field. Data revealed that there was also solar wind. These findings enabled scientists to create a map of the magnetosphere.

6. Northern Lights Solar Particles Move Millions of Miles Per Hour

Today we know the Northern Lights are created by solar flares that shoot through space out of the sun. Specifically the lights originate from collisions between gas molecules on the surface of the sun, releasing large quantities of matter and electromagnetic radiation. The speed at which the solar flares normally travel is around seven million miles per hour (11,265,408 kph). At this speed, the solar flares take anywhere from one to five days to reach Earth, depending on the speed of the solar wind. In comparison, sunlight takes eight minutes to reach Earth. As the solar flares reach the Earth's atmosphere, the majority of the particles continue past Earth into space. However, a few solar flares enter the atmosphere from east to west, above the magnetic poles.

7. The Northern Lights Are Diffuse (Soft) or Discreet (Sharp)

Most auroras occur in a band called the auroral zone, which is at a 3- to 6-degree latitude from the geographical poles. The Northern Lights can be either diffuse or discrete: Diffuse auroras form a featureless glow that may not be visible to the naked eye, while discrete auroras have sharp features and can vary significantly in brightness.

8. Auroral Breakups Bring the Northern Lights to Life

The most spectacular part of watching the Northern Lights, and a common passenger wish on both Greenland cruises and Svalbard cruises around Spitsbergen, is seeing the auroral breakup. This event involves a brightening of forms and a rapid change in the aurora. The lights go from plain to rayed before swirling and dancing in the sky. In fact, multiple breakups can happen on a single night of moderate to high activity, while a low-activity night will have one or two breakups. Scientists advise viewers to stay put if they see multiple bands appearing in an area, as that means a breakup is likely to occur. If these bands are seen early in the evening, the breakup will most likely be spectacular, with many more to come. After a big breakup occurs, there may not be any activity for half an hour to an hour, and breakups themselves can last around that long.

9. Aurora Borealis Colors Come from Gas and Electrons

The colors of the Northern Lights are dependent on gas and electrons in the atmosphere. High-energy electrons cause oxygen to emit green light, while low-energy electrons cause a red light. Nitrogen typically gives off a violet or pink color, while vertical blues are caused by electrons colliding with ionised nitrogen. Another factor that determines the color formation is altitude. At high altitudes (over 105 miles, 170 km) reds are generated, at middle altitudes (60 - 105 miles, 95 - 170 km) green is generated, and at lower altitudes (50 - 60 miles, 80 - 95 km) pink and violet are generated. When there are large solar storms, red can occur at the lower altitudes. The color variations are due to oxygen taking around a second to emit energy as green light, and up to two minutes to emit red light. Higher altitudes contain a greater percentage of atomic nitrogen, giving atoms plenty of time to emit red, while the pinkish colors are a result of red from oxygen and blue from nitrogen combining.

10. Practice Makes Perfect Northern Lights Pics

When taking that perfect photo of the Northern Lights, first check the weather and visit a website for aurora forecasts. A clear sky free of light pollution is as important as having the moon out of range, though some photographers prefer the moon for natural foreground lighting. Another factor is proximity to water, as an aurora over sea or lake can provide an amazing reflection. For this type of photograph, a wide-angle zoom lens is advised. With exposure times ranging usually from 20 - 30 seconds, it is recommended that your camera be secured to a tripod. Also, try not to breathe out in awe while looking through the viewfinder, as this can cause the lens to fog and leave condensation that might later freeze. This might take some practice, but the results will be worth it.

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10 illuminating facts about the northern lights

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10 Illuminating Facts about the Northern Lights

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According to Roman mythology, Aurora was the goddess of the dawn. The word "borealis," however, is Greek for "wind." The combined phrase "aurora borealis" therefore means "dawn wind," known in English as the northern lights.

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Answer

The northern lights, one of several astronomical phenomena called polar lights (aurora polaris), are shafts or curtains of colored light visible on occasion in the night sky.

Aurora borealis - the Northern Lights. Chena Hot Springs, Alaska, 2013. LCDR Gary Barone, NOAA Corps (ret.), photographer. NOAA Photo Library.

Polar lights ( aurora polaris) are a natural phenomenon found in both the northern and southern hemispheres that can be truly awe inspiring. Northern lights are also called by their scientific name, aurora borealis, and southern lights are called aurora australis.

Sten Odenwald, author of The 23rd Cycle: learning to live with a stormy star (New York, Columbia University Press, c2001), provides insight into how northern lights are generated:
The origin of the aurora begins on the surface of the sun when solar activity ejects a cloud of gas. Scientists call this a coronal mass ejection (CME). If one of these reaches earth, taking about 2 to 3 days, it collides with the Earth's magnetic field. This field is invisible, and if you could see its shape, it would make Earth look like a comet with a long magnetic 'tail' stretching a million miles behind Earth in the opposite direction of the sun. When a coronal mass ejection collides with the magnetic field, it causes complex changes to happen to the magnetic tail region. These changes generate currents of charged particles, which then flow along lines of magnetic force into the Polar Regions. These particles are boosted in energy in Earth's upper atmosphere, and when they collide with oxygen and nitrogen atoms, they produce dazzling auroral light.
Odenwald further tells us "Aurora are beautiful, but the invisible flows of particles and magnetism that go on at the same time can damage our electrical power grid and satellites operating in space. This is why scientists are so keen to understand the physics of aurora and solar storms, so we can predict when our technologies may be affected."

Northern Lights over fort at Sitka, Alaska. Prints & Photographs Division, Library of Congress.

Can I see them anywhere?

Yes, although they are more frequent at higher latitudes and places like Alaska, Canada, and Antarctica, closer to the Earth's poles. Occasionally, they have been seen closer to the equator, and even as far south as Mexico. To view them, look in the direction of the closest pole (the northern horizon in the northern hemisphere, the southern horizon in the southern hemisphere).

Can I see them at any time of the year?

Yes. In some areas, such as Alaska or Greenland, they may be visible most nights of the year. And they occur at any time of the day, but we can't see them with the naked eye unless it's dark.

What causes the colors and patterns?

Colors and patterns are from the types of ions or atoms being energized as they collide with the atmosphere and are affected by lines of magnetic force. Displays may take many forms, including rippling curtains, pulsating globs, traveling pulses, or steady glows. Altitude affects the colors. Blue violet/reds occur below 60 miles (100 km), with bright green strongest between 60-150 miles (100-240 km). Above 150 miles (240 km) ruby reds appear.

A panoramic view of McMurdo Station in the middle of winter with the Aurora Australis, the Milky Way, and the streaks of satellites in the night sky. In the distance are the lights of Pegasus White Ice Runway. June, 2016. Joshua Swanson, NSF, photographer. United States Antarctic Program Photo Library, National Science Foundation.

Fun Facts about northern lights

According to Neil Bone (The Aurora: sun-earth interactions, 1996), the term aurora borealis-northern dawn-is jointly credited to have first been used by Pierre Gassendi (1592-1655) and Galileo Galilei (1564-1642), who both witnessed a light display on Sept. 12, 1621. However, Bone also includes a description of the northern lights made 1,000 years prior by Gregory of Tours (538-594.) It included the phrase, "... so bright that you might have thought that day was about to dawn."

Auroras have been observed since ancient times.

The height of the displays can occur up to 1000 km (620 miles), although most are between 80-120 km.

Auroras tend to be more frequent and spectacular during high solar sunspot activity, which cycles over approximately eleven years.

Some displays are particularly spectacular and widespread and have been highlighted in news accounts. Examples include auroral storms of August-September, 1859, Feb 11, 1958, (lights 1250 miles wide circled the Arctic from Oregon to New Hampshire) and March 13, 1989, (the whole sky turned a vivid red and the aurora was seen in Europe and North America as far south as Cuba).

Legends abound in northern cultures to explain the northern lights. Some North American Inuit call the aurora aqsarniit ("football players") and say the spirits of the dead are playing football with the head of a walrus. Often legends warn children that the lights might come down and snatch them away.

June 1896, Norwegian Kristian Birkeland, the "father of modern auroral science," suggested the theory that electrons from sunspots triggered auroras.

Yellowknife (Northwest Territories, Canada) is the capital for aurora tourism.

The earliest known account of northern lights appears to be from a Babylonian clay tablet from observations made by the official astronomers of King Nebuchadnezzar II, 568/567 BC.

Some people claim to hear noises associated with the northern lights, but documenting this phenomenon has been difficult.

Northern Lights, Eielson Air Force Base, Alaska. The Aurora Borealis, or Northern Lights, shines above Bear Lake. The lights are the result of solar particles colliding with gases in Earth's atmosphere. Early Eskimos and Indians believed different legends about the Northern Lights, such as that they were the souls of animals dancing in the sky or the souls of fallen enemies trying to rise again. Senior Airman Joshua Strang, U.S. Air Force photographer. U.S. Air Force Media Gallery.

Published: 11/19/2019. Author: Science Reference Section, Library of Congress

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The northern lights, one of several astronomical phenomena called polar lights (aurora polaris), are shafts or curtains of colored light visible on occasion in the night sky. Aurora borealis - the Northern Lights. Chena Hot Springs, Alaska, 2013. LCDR Gary Barone, NOAA Corps (ret.), photographer. NOAA Photo Library.

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Create a new document and edit with others at the same time -- from your computer, phone or tablet. Get stuff done with or without an internet connection. Use Docs to edit Word files. Free from Google.