Aurora Explained: What Causes The Northern Lights And Southern Lights?
Ever dreamed of seeing the sky come alive with shimmering waves of green and red light? The northern and southern lights — aurora borealis and aurora australis — are among Earth’s most magical natural displays. In this guide, you'll discover what causes auroras, the best times and places to see them, and why they are especially active right now. Use the Sky Tonight app to find the darkest nights and ideal conditions for spotting auroras. Don’t miss your chance to witness nature’s ultimate light show!
Contents
- What is an aurora?
- What causes the northern and southern lights?
- When is the best time to see auroras?
- Where can you see the aurora borealis and aurora australis?
- How to see an aurora?
- Aurora myths and legends
- F.A.Q.
- Northern lights and southern lights: conclusion
What is an aurora?
An aurora is a beautiful light display in the sky near Earth's polar regions. An aurora in the Northern Hemisphere is called the aurora borealis or northern lights, and in the Southern Hemisphere, it is known as the aurora australis or southern lights.
The Latin word “aurora” to describe this mesmerizing natural wonder was first coined by Galileo Galilei in 1619, who named it after the Roman goddess of dawn. The words “borealis” and “australis” come from the names of the Greco-Roman gods of the north and south winds, Boreas and Auster, respectively.
What causes the northern and southern lights?
The northern and southern lights occur when charged particles from the Sun (the solar wind and bursts from solar storms) collide with gases in Earth's upper atmosphere (mostly oxygen and nitrogen). These particles are directed by Earth’s magnetic field toward the poles.
Auroras appear between 97 and 1,000 kilometers above Earth, forming vibrant curtains, spirals, coronas, rays, and other forms. These shapes follow magnetic field lines. Adding to their marvel, auroras seem to “dance,” constantly changing with Earth’s rotation and bursts of solar energy.
Why auroras are stronger now: the solar maximum
Auroras are closely tied to solar activity, which follows an 11-year cycle with alternating periods of high and low intensity. The most active phase of the cycle is called solar maximum. During this time, the Sun produces more sunspots, solar flares, and coronal mass ejections (CMEs). These powerful eruptions send streams of charged particles toward Earth, intensifying the aurora borealis and aurora australis.
Solar Cycle 25 has exceeded its predicted peak in August 2024, but solar activity is expected to remain strong through early 2026. Thanks to it, auroras are appearing more often, glowing more vividly, and extending farther from the poles, even reaching regions that rarely experience them.
The Sun lights up your days, but do you really know it? Discover its secrets — from sunspots to the core — in our fun quiz!
When is the best time to see auroras?
The best chances to see auroras come when three conditions align: dark skies, clear weather, and high solar activity. This is why winter, the New Moon, and periods of solar maximum are the most favorable times in both hemispheres. Additionally, equinoxes are the times when auroras are especially active.
During winter, nights are longer, especially near the poles, where the Sun doesn't rise at all during the polar night. With the Moon out of sight during its new phase, the sky is even darker, making auroras easier to spot.
However, darkness alone isn’t enough; auroras also depend on the interaction between the solar wind and Earth’s magnetic field. This is where the equinoxes come in. As Earth orbits the Sun, its axial tilt causes the angle between its magnetic field and the solar wind to shift. Around the equinoxes, the alignment is optimal, creating temporary “cracks” in the magnetosphere. These openings allow more solar particles to enter, increasing the likelihood of visible auroras.
When is the best time to see the northern lights?
The aurora borealis is most likely to be visible from late August to mid-April. Although auroras occur year-round, they are too faint to be seen in daylight. This makes sightings virtually impossible from May through early August in the far north during the polar day, and more difficult in other northern areas with extended daylight hours.
March and September, around the time of the equinoxes, provide better aurora activity. Meanwhile, in December and January, the nights are the longest and darkest, offering prime conditions for extended skywatching.
Auroras can appear at any time during darkness, but the strongest displays typically occur between 9 p.m. and 2 a.m., with a peak often seen around 11 p.m. to midnight. During daylight hours (roughly 4 a.m. to 5 p.m.), the sky is usually too bright to see them, unless you are in a high-latitude location like Svalbard, where it remains dark 24 hours a day from mid-November to late January.
When is the best time to see the southern lights?
The aurora australis can be observed from March to September. Although auroras occur year-round, they are too faint to be seen in daylight. This makes sightings virtually impossible from October through early March in the far south during the polar day, and more difficult in other southern areas with extended daylight hours.
June and July offer the longest, darkest nights, while March and September typically bring higher auroral activity. Aurora displays are most likely between 9 p.m. and 2 a.m., with peak visibility around 11 p.m. to midnight. During daylight hours (roughly 4 a.m. to 5 p.m.), the sky is usually too bright to see auroras — unless you're in Antarctica, where the polar night allows for 24-hour darkness, though it's a challenging and remote spot for aurora viewing.
How long do the northern and southern lights last?
Some auroras last only a few minutes, while others can stretch on for hours. On average, a strong display lasts about 15 to 30 minutes, but multiple waves of auroras can appear throughout the night, especially during periods of heightened solar and geomagnetic activity, for example, around equinoxes.
The intensity and duration can vary greatly from one night to the next, making every aurora sighting unique. This unpredictability is part of what makes aurora hunting so exciting — you never know when the sky might suddenly light up.
Where can you see the aurora borealis and aurora australis?
Auroras are most frequently seen within the auroral zone, a belt about 6° wide centered around 67° north and south latitude. The area where auroras appear at any given moment is called the auroral oval.
During geomagnetic storms, these ovals can expand, allowing auroras to be seen much farther from the poles. The aurora borealis has occasionally reached as far south as the Mediterranean and the southern United States, while the aurora australis has been visible as far north as New Caledonia and Western Australia’s Pilbara region. One of the most extreme cases was the Carrington Event in 1859, when auroras were seen even in the *tropics.
Best places to see the aurora borealis (northern lights)
Here are some of the popular and accessible destinations to observe the northern lights:
- Norway – Tromsø, Alta, and the Lofoten Islands
- Sweden – Abisko and Kiruna in Swedish Lapland
- Finland – Rovaniemi and areas north of the Arctic Circle
- Russia – The Murmansk region, including Teriberka and the Kola Peninsula
- Iceland – Almost the entire country offers excellent visibility
- Canada – Yukon, Northwest Territories, Nunavut, and northern Alberta
- Alaska (USA) – Fairbanks and Denali National Park
During strong geomagnetic storms, the northern lights can occasionally be seen much farther south, reaching parts of Scotland, northern U.S. states (like Minnesota, Michigan, and Maine), and even lower latitudes.
Best places to see the aurora australis (southern lights)
The aurora australis is harder to spot due to the vast oceans surrounding the South Pole and fewer populated areas at high southern latitudes. Still, some places offer great viewing potential:
- Tasmania (Australia) – Areas south of Hobart and remote beaches like Cockle Creek
- New Zealand – The South Island, particularly around Dunedin, Invercargill, and Stewart Island
- Southern Argentina and Chile (Patagonia) – Here auroras are occasionally visible during strong solar storms
- Sub-Antarctic islands – Such as South Georgia or the Falklands (for expeditions or researchers)
- Antarctica – The most active region for the southern lights, but also the least accessible
How to see an aurora?
Here is how to increase your chances of witnessing the northern lights (aurora borealis) or southern lights (aurora australis):
- Choose the ideal location
Aim for locations within or near the auroral zones, but keep in mind that some areas closer to the poles can have harsh or unpredictable weather. Check the recommended spots listed in the Best places to see auroras section of this article.
- Time it well
The northern lights are visible from September to March, and the southern lights can be seen from March to September. The optimal viewing hours are from 9 p.m. to 2 a.m., especially from 11 p.m. to midnight.
- Monitor aurora forecasts
Use websites like Space Weather Prediction Centre and SpaceWeatherLive to stay updated on upcoming aurora activity. Watch the Kp index — a value of 5 or higher means there's a good chance of seeing strong auroras.
- Seek clear dark skies
Avoid city lights to keep the skies as dark as possible. Plan your aurora hunt around the New Moon for minimal natural light, and aim for nights with clear skies and low cloud cover.
To easily find the darkest night for aurora viewing, use the Sky Tonight app. It features a Stargazing Index that combines the Moon phase, weather conditions, and light pollution to show how good the observing conditions are tonight. In the app's calendar, you can check the Moon phases for each day, and see when total darkness begins and how long it lasts.
- Face the best direction
Once you're at your viewing spot, face north in the Northern Hemisphere and south in the Southern Hemisphere. Make sure you have a wide, clear view of the horizon.
- Warm up and stay patient
Dress warmly and bring a blanket or chair for comfort. Avoid looking at bright light sources, so your eyes can adjust to the dark. While you wait, use Sky Tonight in night mode to explore stars and planets — it’ll make the time pass more enjoyably.
With the right conditions and a bit of luck, you’ll be rewarded with one of nature’s most awe-inspiring sights!
Aurora myths and legends
Throughout history, people have looked to the glowing skies with awe and curiosity, crafting rich stories to explain the mysterious lights. Here are some of the most fascinating aurora myths from around the world.
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Scandinavia: The Vikings believed the northern lights were the reflections of shining weapons of Valkyries guiding fallen warriors to Valhalla.
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Finland: The Sámi people thought that auroras were caused by a magical fox sweeping snow into the sky with its tail — that’s why the Finnish word for auroras is translated as “fox fires.”
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Siberia: The Chuvash believed the aurora borealis was a flying snake and a god of childbearing who distributes souls of babies.
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Greenland: The Inuits considered auroras to be the souls of the dead playing football with a walrus skull.
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North America: The Algonquin people thought auroras were fires lit by their creator, Nanahbozho, to remind them of him and to watch over them.
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New Zealand: The Maori saw the aurora australis as the reflected glow of torches or campfires lit by their ancestors, who had journeyed south and settled in those distant lands.
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Australia: The Aboriginal Australians interpreted the aurora australis as fires in the spirit world or omens from ancestral beings.
F.A.Q.
Why do the auroras have different colors?
Aurora colors depend on the type of gas in the atmosphere and the altitude where the charged particles collide with it:
- Green – Caused by oxygen at altitudes of about 100 to 300 km
- Red – Also from oxygen, but higher up, above 150 km
- Blue/Purple – Produced by nitrogen at lower altitudes
- Pink/Yellow: Rare blends of red with green or blue, seen during high solar activity
The most common aurora colors are red and green.
Are the northern and southern lights really that colorful?
Yes, the northern and southern lights can be marvelously colorful, but what you see with the naked eye is usually less vivid than in photos. Green is the most common and visible color, while reds, purples, and blues often appear faint or grayish in real time. Light pollution and clouds may also obscure the view. However, under very dark conditions with strong aurora activity, you may naturally see a wide range of colors.
Is there a difference between the northern and southern lights?
The northern and southern lights are essentially the same natural phenomenon. However, they are viewed from opposite poles of Earth, and their visibility seasons are reversed. Auroras in both hemispheres occur simultaneously and in similar patterns, but there may be slight differences in their shapes and timing due to variations in the Earth's magnetic field and the direction of the solar wind. Also, the aurora borealis is better known and more frequently observed because it’s easier to reach high-latitude locations in the Northern Hemisphere.
Are auroras dangerous?
Auroras occur so high up in the atmosphere that they don’t pose any danger to people watching them on the ground. However, the solar storms that trigger strong auroras can impact technology, potentially disrupting GPS, radio signals, and satellite operations.
Are there auroras on other planets?
Auroras aren’t exclusive to Earth — they can be found on other planets too, as long as they have a magnetic field and an atmosphere. The only Solar System planet that doesn’t have auroras at all is Mercury, since it lacks a substantial atmosphere and is located too close to the Sun.
Northern lights and southern lights: conclusion
The northern and southern lights (aurora borealis and aurora australis) are among the most mesmerizing natural wonders on Earth — dancing waves of light that can be seen with the naked eye. They’re a result of solar wind interacting with Earth’s magnetic field, and right now, they’re more active than they’ve been in over a decade!
The best chances to see auroras come when solar activity is high, the nights are darkest, and you’re in a low light pollution area close to the poles. Use the Sky Tonight app to find the darkest night and plan ahead for the perfect viewing conditions. Save this article so you can come back to it when your ideal aurora night approaches.
Wishing you clear skies and a stunning display of colorful auroras!
