The Northern Lights are recognized as one of the most significant natural wonders of the world. For generations, humans have marveled in delight at the natural colors of auroras, watching the night sky come alive in a brilliant mosaic of blues and greens. In recent years, aurora tourism in the Arctic has become a major industry, with many tourists from around the world making the journey to see the Northern Lights. With that in mind, you may be asking: can the Northern Lights be seen from space?
The answer is yes. While space aurora sightings are uncommon due to the limited number of astronauts in orbit at any given time, auroras are indeed visible from outer space. Read on to learn more.
Can the Northern Lights Be Viewed from Space?
The Northern Lights is a phenomenon that originates in outer space, specifically as a result of the Earth’s interaction with the sun. The sun regularly emits solar wind, a stream of charged particles that radiate outwards into the solar system. Solar wind contains dangerous radiation and is fatal to human life, but the magnetosphere, the protective barrier created by Earth’s magnetic field, deflects and defuses solar wind before it is able to reach Earth’s surface
Earth’s magnetosphere is projected outward from the planet into outer space, only converging with the atmosphere at two points: the North and South Poles, from which the Earth’s magnetic field is generated. When solar wind enters the atmosphere at these points, charged particles within the solar wind interact with atmospheric particles to produce the Northern Lights.
All matter is made up of atoms, and atoms themselves are made up of protons, neutrons, and electrons. Protons have a positive electrical charge, neutrons no charge, and electrons a negative charge. Protons and neutrons are located in the nucleus of the atom, with electrons orbiting the nucleus in the same way that the Earth orbits the sun.
When charged particles interact with air molecules in the atmosphere, the electrons become excited, moving to higher-energy orbits that are further away from the nucleus. When the electrons cease being excited, they return to their original orbits, giving off a photon—a unit of light—in the process. When this process happens to many air atoms all at once, it generates auroras. The effect is similar to a neon sign, which uses electricity to excite atoms of neon gas, producing light.
Because auroras occur within the atmosphere, it was previously believed that they were only visible from Earth’s surface. However, recent pictures from the International Space Station have confirmed the visibility of auroras from outer space. Due to the fact that spacecraft and space stations observe auroras from above rather than below, as people on Earth do, auroras have a considerably different appearance when seen from orbit.
In outer space, auroras appear as giant circles of blue, green, or red light formed around the planet’s poles. Like on Earth, the sun’s presence makes it impossible for auroras to form due to sunlight causing the aurora to dissipate. As a result, in order to observe an aurora from space, the pole where it is occurring must be at least partially shrouded in darkness.
This means that auroras are more commonly seen during periods in which one pole is tilted away from the sun. Earth’s axial tilt means that one pole is facing the sun for six months out of the year. During fall and winter in the northern hemisphere (September through March), the North Pole is tilted away from the sun and the South Pole is tilted towards it, while from March to September, the reverse is true. This cycle is responsible for creating the seasons, as the hemisphere that is facing the sun receives more sunlight, causing summer, while the hemisphere facing away receives less sunlight, resulting in the cold temperatures of winter.
With the discovery that auroras are visible from space, many space agencies have set up tools to specifically monitor them. Auroras are a common sight on the International Space Station, with many astronauts sharing pictures of them on the Internet. NASA maintains a number of spacecraft dedicated to monitoring auroras and photographing them as part of their greater mission to study outer space and potential threats to life on Earth. Other countries’ space agencies have also taken an intense interest in auroras.
Auroras are some of the most striking sights that planet Earth has to offer, whether you see them on the ground or from space. Fortunately, seeing an aurora doesn’t require you to be an astronaut; you merely need to visit the Arctic during prime viewing season. If you’re curious about watching auroras, book a tour and prepare for one of the most memorable vacations of your life, an experience you will remember for years to come.