The North Pole is known for its extreme weather and long periods of darkness. But sometimes, the sky above the frozen land can surprise us with a splash of color. Recently, a photographer captured a stunning sight of pink auroras during the daytime, a phenomenon that is rarely seen and poorly understood.

What are auroras and how do they form?

Auroras, also known as the Northern Lights or the Southern Lights, are natural light shows that occur in the polar regions of the Earth. They are caused by the interaction of charged particles from the sun with molecules in the Earth’s atmosphere, which emit light of different colors depending on the type and altitude of the molecules.

The sun constantly emits streams of charged particles, called the solar wind, that travel through space and reach the Earth. Some of these particles are deflected by the Earth’s magnetic field, but some can enter the atmosphere through the openings near the poles. When these particles collide with oxygen and nitrogen molecules, they transfer some of their energy to them, causing them to glow. Oxygen molecules tend to emit green or red light, while nitrogen molecules tend to emit blue or purple light.

Why are auroras usually seen at night?

Auroras are more visible at night because the contrast between the dark sky and the bright colors makes them stand out. During the day, the sunlight washes out the auroras, making them harder to see. However, there are some exceptions to this rule.

Sometimes, the sun can produce powerful bursts of energy, called solar flares or coronal mass ejections, that can enhance the solar wind and increase the intensity of the auroras. If these events happen when the sun is facing the Earth, the auroras can become bright enough to be seen during the day, especially near the poles where the sunlight is weaker.

Another factor that affects the visibility of the auroras is the season. The Earth’s axis is tilted by about 23.5 degrees, which means that the poles experience different amounts of daylight and darkness throughout the year. During the winter, the pole that is tilted away from the sun experiences the polar night, a period of continuous darkness that lasts for several weeks or months. During the summer, the opposite happens, and the pole that is tilted toward the sun experiences the polar day, a period of continuous daylight that lasts for the same duration. During these periods, the auroras can be seen at any time of the day or night, depending on the solar activity and the weather conditions.

Why did the sky turn pink?

The pink sky that was observed by Marjan Spijkers, a photographer from Svalbard, an archipelago located about 1300 kilometers south of the North Pole, was a rare and beautiful phenomenon that resulted from a combination of factors.

Spijkers witnessed the pink sky on December 1st, when Svalbard was in the middle of the polar night. The sun had not risen above the horizon since early October, and the darkness allowed the auroras to be visible even at noon. However, the sky was not completely dark, as there was still some faint daylight coming from the sun’s position below the horizon. This daylight mixed with the red light emitted by the oxygen molecules in the upper atmosphere, creating a pink hue that covered the sky.

The pink sky also coincided with the growth of a sunspot, called AR3513, that had been producing M-class solar flares. These flares increased the number and energy of the solar particles that reached the Earth, making the auroras more intense and widespread. As the sunspot turned toward the Earth later in the week, these flares became more geoeffective, meaning that they had a stronger impact on the Earth’s magnetic field and atmosphere.

The pink auroras that Spijkers captured were particularly unique because they occurred on the dayside of the Earth, where the solar particles enter the atmosphere through the opening in the magnetic field that faces the sun. This is different from the more common nightside auroras, where the solar particles enter the atmosphere through the opening in the magnetic field that trails behind the Earth. There have been too few sightings of the dayside auroras to understand if there is a difference in their appearance or behavior from the nightside auroras.

What does this phenomenon tell us about the Earth and the sun?

The pink sky at the North Pole is a reminder of the dynamic and ever-changing nature of the Earth and the sun, and their complex relationship. The Earth and the sun are constantly interacting through the solar wind, the magnetic field, and the atmosphere, creating a variety of phenomena that affect our planet and our lives. Some of these phenomena, such as the auroras, are beautiful and harmless, while others, such as the geomagnetic storms, can pose a threat to our technology and infrastructure.

By studying and observing these phenomena, we can learn more about the physics and chemistry of the Earth and the sun, and how they influence each other. We can also improve our ability to predict and prepare for the potential impacts of the solar activity on our planet and our society.