Appearing as dark rings or blobs against the illuminated sky, black auroras are voids in the northern and southern lights.

Interactions between solar storms and Earth's magnetic field create auroras

Solar storms on the Sun's surface produce clouds of electrically charged particles, some of which make their way to Earth. Those trapped in Earth's magnetic field accelerate toward the north and south poles, colliding with atmospheric atoms and molecules in the process, which produces light.

Auroras take place all day long, but are too faint to see during the day

Because the sun constantly emits charged particles into the solar system, Earth's magnetic field deflects them continuously, with a small subset becoming trapped and colliding with atmospheric gases. Daylight, light pollution, and weather prevent the northern and southern lights from being seen most of the time, even for those at higher latitudes.

See the 25 of the best photos of auroras from around the world.

The sun and Earth's liquid outer core help create the northern and southern lights

Earth's magnetosphere, generated by the movement of molten iron deep within the planet, consists of a magnetic field that deflects charged particles north and south. Some of the particles released by the sun in the solar wind become trapped in this field and are propelled toward the poles, where they produce auroras through collisions with atmospheric particles.

The best location to view auroras is within the auroral oval

Earth's magnetic field pushes trapped particles from the solar wind toward the planet's magnetic poles, where they can descend and collide with atmospheric gases in a ring located between 60 and 75 degrees of latitude. Auroras can also be viewed at lower latitudes—the sub-auroral oval and solar storm zones—if the sun produces powerful solar storms.

The colors of auroras change with the intensity of solar activity and with altitude because of differences in atmospheric density and chemical composition.

High solar activity can produce pink and purple auroras

Although less common, energetic enough charged particles from the sun that descend to an altitude of about 100 kilometers (62 miles) can strike a mixture of ionized and neutral nitrogen molecules, causing them to emit red and blue light, which our eyes perceive as purple.

Aurora borealis and auroras australis do not always mirror one another

While the Earth's magnetic field is symmetric across the magnetic north and south poles in isolation, charged particles from the sun distort the field. If the angle of impact between the wave of particles and the Earth's field is such that the distortions are uneven, dissimilar geomagnetic storms and resulting auroras are produced in the northern and southern hemispheres.

Coronal mass ejections and solar flares produce the most extensive auroras

The most intense geomagnetic storms are produced when massive clouds of plasma—ionized gas—are expelled from the sun's upper atmosphere and interact with the Earth's magnetic field. These storms expand where auroras are bright enough to be seen to regions farther from the poles, particularly during peak periods of the sun's 11-year intensity cycle.

Planeterrellas create artificial auroras that mimic the atmospheric displays of light by setting up an electric field between two metal balls in a jar filled with a small amount of air.

Crackling, popping, and rustling sounds have been reported during auroras

At the altitudes where auroras take place—between 100 and 300 kilometers (62 to 186 miles)—air is not dense enough to efficiently vibrate and carry sound waves to the ground. However, one theory suggests that the geomagnetic energy behind auroras can trigger electrical discharges near the surface, which may be the cause of reported sounds.

In 2025, astronomers confirmed that Neptune has auroras, which were observed at mid-latitudes because its magnetic field is tilted 47 degrees from its rotation axis.

Except for Mercury, every planet in the solar system experiences auroras

Lacking magnetic fields, Venus and Mars exhibit auroras when the solar wind collides directly with their atmospheres, without deflection. Some particles behind the atmospheric collisions that generate auroras on gas giants come from their moons and the surrounding environments.

View a gallery of various auroral shapes

Auroras can be generally classified as discrete (well-defined shapes) or diffuse (hazy shapes), with light taking various forms, including curtains, arcs, pillars, and rays. Some auroras can also pulsate, particularly after intense periods of auroral activity are winding down.

Aurora-like magenta streaks across the sky may not be auroras

The phenomenon, known as STEVE (Strong Thermal Emission Velocity Enhancement), has only been observed alongside auroras. Rather than light emitted by gases energized by collisions with ionized particles from the sun, STEVE is a high-velocity, high-temperature stream of particles that glows. (Some readers may experience a paywall.)

The impacts of the solar maximum on Earth, from telecommunications to auroras

During the peak of the sun's 11-year cycle, plasma emissions stronger than the average stream of particles from the sun can compress and distort the Earth's magnetic field, allowing auroras to be seen farther from the poles. Distortions in the ionized layer of Earth's atmosphere can also alter the path of communication transmissions through the air. (Some readers may experience a paywall.)

The intensity of auroral activity approximately follows the sun's 11-year cycle

The density, speed, and temperature of material ejected by the sun are at their lowest at the start of each cycle, resulting in weaker interactions with Earth's magnetic field and muted, diffuse auroras. While the average solar wind speed is about 300 kilometers (186 miles) per second, the fastest winds can be more than three times faster.

Scientists quantify how far from the poles auroras will be visible using the G-scale

The Geomagnetic Storm scale indicates the expected severity of the deformation of Earth's magnetic field based on the amount of energy injected by the solar wind. Solar activity is monitored using various satellites to forecast these storms, which can also be used to anticipate damage and disruption to power systems, radio communications, and satellite navigation.

Scientists have tested atmospheric models by firing rockets into the aurora borealis

Functioning like components of a CT scan, the missiles transmit signals that can be used to identify charged particles and electromagnetic currents in slices. The slices are then combined to construct a computer-based model of Earth's atmospheric structure, which is used to compare the accuracy of physics-based models.

East Asian records of auroras may date back to 10,000 BCE

Ancient texts from Japan, Babylon, and China contain accounts of auroras dating back millennia. Because auroral activity and intensity are driven by periodic ebbs and flows in solar activity, these records allow scientists to identify patterns that may help anticipate particularly dangerous future solar storms.

A basic camera setup or a phone is enough to capture stunning aurora photos

Auroras result from solar particles interacting with atmospheric elements. This article provides tips on improving the quality of aurora photos taken with simple equipment and the best times and locations to yield better photos.

Rare chance for US states to see Northern Lights

A solar storm in July 2023 offered people in 17 American states, as well as Canada, an unusual chance to witness the Northern Lights, or aurora borealis. The 11-year solar cycle, reaching its peak in 2024, made the lights visible in places further south than usual. Read up on the announcement from the Geophysical Institute at the University of Alaska at Fairbanks here.

Earth's magnetic field can trap high-energy charged particles produced by the sun and distant cosmic events in doughnut-shaped rings called Van Allen belts.

Explore a guide to photographing auroras

Using a wide aperture and increasing your camera's native ISO to a value between 3200 and 8000, depending on atmospheric conditions, will help capture as much light as possible while freezing the movement of the auroras. The camera should also be kept as still as possible and in environments with minimal weather impediments, such as clouds.

Aurora-related activities drive significant tourism in regions near the Arctic Circle

As the peak solar cycle approached from late 2024 to early 2026, airlines serving countries such as Iceland, Finland, and Canada increased their scheduled flights, with direct flights to Tromsø, Norway, doubling since 2018. The northern lights tourism market has grown about 10% per year and is expected to increase from $941.9M in 2024 to $1.648B in 2030.

Research shows that cosmic rays may trigger the cascade of displaced electrons needed to produce lightning, which is also enabled by pointed ice crystals that create strong electric fields.

The scientific name for northern lights came from two Greco-Roman gods

Although cave paintings may have depicted them millennia earlier, one of the oldest known references to auroras is a Babylonian cuneiform tablet from about 600 BCE. In 1619, Galileo Galilei named the phenomenon in the northern hemisphere "aurora borealis" after the Roman goddess of dawn—Aurora—and the Greek god of the north wind—Boreas.

Colorful thunderstorm phenomena can be viewed from the International Space Station

Transient luminous events are lightning-related phenomena that occur in the atmosphere above storm clouds. These events often look like columns of red light resulting from electrical discharge, but may also appear as purple tendrils or long blue jets.

Lightning is the sudden flow of electricity in the atmosphere as two oppositely charged regions seek to become balanced via the movement of electrons.

An exoplanet detection method involves measuring a host star's auroras

Astronomers have reported indirectly identifying a planet by observing its debris interacting with the magnetic field of the star it orbits. The interaction is a larger-scale version of the auroras observed on Jupiter, which are produced when material released by its moon, Io, interacts with the gas giant's magnetic field.

Dark stars are hypothetical stars that would have existed in the early universe

Primarily composed of visible matter, this celestial object would also contain a significant amount of dark matter that would annihilate with itself, converting its mass into energy. This energy would prevent the star from collapsing under its own gravity and from triggering nuclear fusion until its dark matter fuel was exhausted.

NASA's James Webb Space Telescope captures enormous aurora displays on Jupiter

The auroras flicker faster and brighter than those seen on Earth. This contrasts with earlier predictions that the lights would fade slowly over several minutes, providing insights into how Jupiter's magnetosphere operates.

Antimatter can be created from dark lightning—high-energy light emitted by deflected electrons after they are accelerated to near the speed of light by thunderstorms.

Lightning forms when streams of rising and falling charged particles connect

In cloud-to-ground lightning, a buildup of negative charge at the bottom of clouds repels electrons on Earth's surface, leaving behind positively charged particles. When descending negatively charged air—the stepped leader—meets rising positively charged particles—the upward streamer—brightening runs up the connection, producing intense flashes known as return strokes.

Auroral myths include Valkyries, firefoxes, and torchlight from giants fishing at night

In Norse mythology, the light displays were considered reflections from the Valkyries' armor as the female warriors brought the souls of heroes to Valhalla. In Finland, firefoxes were thought to move so fast that they created sparks in the sky as their tails brushed against mountains.

Space weather, including solar flares and coronal mass ejections, is driven by the sun's magnetic field and can affect Earth's ground- and space-based technological systems.

Light echoes are expanding shells of reflected starlight

Just as sound waves reveal the location of obstacles by reflecting off them, pulses of light emitted by stars illuminate rings of interstellar dust, giving the appearance of ejected material as the light travels outward.

View the transparency of Earth's atmosphere and how it blocks most forms of light

The gases that make up Earth's atmosphere block most harmful forms of electromagnetic radiation from reaching the planet's surface, except for some ultraviolet light. Their transparency to radio waves means this form of light can reach Earth's surface, which is why most radio telescopes are ground-based rather than space-based.

Photographer catches stunning shot of an aurora over an Icelandic waterfall

Photographer Cari Letelier captured a stunning shot of the aurora borealis over the Godafoss waterfall in Iceland, a composite image pulled from nearly three dozen exposures. The aurora phenomenon is typically visible in Earth's northern latitudes...

The strongest recorded geomagnetic storm in history created auroras near the equator

On Sept. 1, 1859, the Carrington Event—named after the astronomer who observed the preceding solar flare—saw a massive coronal mass ejection strike Earth, disrupting telegraph systems, sparking electrical fires, and reportedly illuminating the night sky enough to allow newspapers to be read at night.

Perseverance captures an aurora on Mars

The Perseverance rover captured the first visible Martian aurora, offering insights into Mars's atmospheric interactions. A coronal mass ejection likely triggered the aurora since the planet lacks a global magnetic field.

The movement of molten metal around Earth's inner core creates the planet's magnetic field, whose north and south poles do not align with the planet's geographic poles.

Explore a gallery of astronomical images curated by the European Space Agency, which includes illustrations and images of aurorae, planets, stars, galaxies, stellar nurseries, exoplanets, and black holes.

Watch a 4K time-lapse of auroras seen from the International Space Station

The video was created from 711 photos taken by European Space Agency astronaut Paolo Nespoli on Sept. 15, 2017, as part of the Vitality, Innovation, Technology, and Ability mission.

Breaking down the ionosphere, which reflects radio waves from Earth's surface

Made up of ionized regions within the mesosphere and thermosphere, the ionosphere contains charged particles produced when solar radiation knocks electrons free from atoms and molecules in the atmosphere. Before satellites, radio operators would bounce signals off these regions to wrap around the planet and extend the range of transmissions.

Understanding why charged particles from the sun protect Earth from more dangerous particles

The solar wind engulfs the solar system in a protective bubble called the heliosphere, which was first theorized in the late 1950s based on studies of cosmic rays—high-energy particles traveling through space at near light speed. The heliosphere shields the solar system from much of this ionizing radiation originating elsewhere in the Milky Way.

The sun emits a continuous stream of plasma known as the solar wind

Composed of charged particles—electrons and ions—the solar wind is deflected around the Earth by the planet's magnetic field. More powerful solar storms, known as coronal mass ejections, are short-lived but produce huge clouds of plasma that disrupt technology upon reaching Earth.

As seen in the dark region of the Horsehead Nebula, clouds of space dust can block some forms of light from reaching telescopes, impairing observations and data collection.

Atmospheric composition and temperature impact the color of lightning

Just as fire ranges from red to blue with increasing temperature, lightning's blueish-white comes from the superheating of air. The emission of light from the predominantly nitrogen- and oxygen-rich atmosphere produces a purple tint, with additional color caused by light scattering from humidity, hail, dust, and ash.

The faint triangle of light occasionally seen above the horizon, known as zodiacal light, is due to sunlight reflecting off ice and dust scattered throughout the inner solar system.