The Northern and Southern Lights (Aurora Borealis and Aurora Australis) are among the planet’s most majestic light shows. These ethereal curtains of color shimmer across the polar night sky, inspiring wonder. This dramatic visual effect often leads travelers to ask: can an aircraft actually fly through the shimmering light of the aurora?
The Physics of the Aurora: Composition and Altitude
The Northern Lights are not a solid object or a weather phenomenon, but a display of light emitted from highly energized gas particles. The process begins when charged particles, primarily electrons and protons from the sun’s solar wind, are guided by Earth’s magnetic field toward the polar regions. Once they enter the upper atmosphere, these particles collide with atoms and molecules of gases like oxygen and nitrogen.
These collisions excite the atmospheric gases, causing them to release energy in the form of photons, which is the light we see. This is similar to how a neon sign works, where electricity excites gas inside a tube to produce a glow. The most common color, green, is produced by oxygen atoms at an altitude of around 100 kilometers (62 miles).
The altitude of the auroral display is the most telling factor. The lowest edge of a typical aurora starts at about 80 to 100 kilometers above the Earth’s surface. The light then extends much higher, sometimes reaching several hundred kilometers into space. This positioning places the light show far above the altitudes where conventional air travel occurs.
The Direct Answer: Can Aircraft Pass Through the Light?
The simple answer is that aircraft regularly fly through the area where the aurora is visible. Commercial airplanes typically cruise at altitudes between 10 and 12 kilometers (33,000 to 40,000 feet) to maximize fuel efficiency and avoid weather. Because the aurora begins at least 80 kilometers above this level, a plane flying beneath it is passing through the visual display without entering the physical region where the light is generated.
The light itself is not a physical barrier or a dense cloud, but an optical effect of extremely dispersed particles. Flying “through” a curtain of aurora is comparable to flying through a beam of sunlight. The air density at the aurora’s altitude is so thin that it is considered a near-vacuum, far too thin to support the aerodynamics of a jet airplane. Therefore, the passage of an aircraft has no physical interaction with the light itself.
Flying High: Navigating the Auroral Zone
While planes fly well beneath the actual light production, routes that cross the high-latitude regions, known as the auroral zone, are still affected by the solar activity that creates the light. The charged particles that cause the aurora can disrupt the upper atmospheric layer called the ionosphere. This disturbance creates challenges for communication and navigation systems on polar flights.
Ionospheric disruption can cause high-frequency (HF) radio blackouts, which are utilized for long-distance communication when satellite links are unreliable. Geomagnetic activity can also introduce errors into Global Positioning System (GPS) signals. Pilots and air traffic control must monitor solar weather forecasts and be prepared to use alternative navigation procedures or communication relays when flying near the poles.
Flying in the auroral zone also involves consideration regarding radiation exposure. Earth’s magnetic field is weakest near the poles, offering less protection from cosmic rays and solar energetic particles. During intense solar activity, the radiation dose at cruising altitude increases slightly, though it remains within safety limits for passengers. Aircrews who fly these polar routes frequently are monitored for cumulative exposure.
For passengers, the interaction with the aurora is purely visual. Pilots often dim the cabin lights and make small, safe deviations from the flight path to provide passengers on both sides of the aircraft with a better view. This practice ensures that the primary effect of flying in the auroral zone is a spectacular sight, rather than a physical hazard to the flight.