What Are the Northern Lights?
An aurora, known as the northern lights (aurora borealis) in the northern hemisphere and the southern lights (aurora australis) in the southern hemisphere, is a natural phenomenon that paints the night sky with unearthly surreal colors. The bright lights of the aurora result from collisions by electrically charged elements from the Sun entering the Earth’s atmosphere.
When Is the Best Time to See the Northern Lights?
Geophysical research conducted in the 1950s revealed that the aurora activity is a cyclic activity and difficult to predict. The auroras are best seen in the northern and southern hemisphere during winter when there are longer episodes of darkness providing clear skies to view the displays. They appear as irregular mirror images centered on each magnetic pole at the same time, in comparable colors and shapes.
The aurora phenomena ensue near the magnetic poles, and they clearest in regions not prone to light pollution such as in North America, the western hemisphere and the southern end of Greenland. However, only the northern lights are visible from these regions as the southern lights are clustered in a ring around the Antarctica.
Mythical Origins of the Auroras
Many cultures have different myths referring to the northern lights. In Roman myths, Aurora was considered to be the goddess of dawn. In medieval times, they were believed to be harbingers signifying war or famine. Some of the native cultures in North America and Europe perceived the aurora to be reflections of torches or campfires. Others believed that the lights represented the spirits of their legendary hunters and fishermen. In Alaska, aurora lights were considered to be the spirits of animals such as seals, whales, and salmons, which they hunted for food.
Causes of the Northern Lights
The northern lights are a result of collisions of electrically charged molecules from the Sun and the Earth’s atmosphere. Every eleven years, the sun goes through a solar cycle experiencing a solar maximum and solar minimum period when protons and electrons are released. Since the temperatures above the surface of the Sun are high measuring over a million degrees Celsius, the collision of gas molecules is often rampant and explosive. Free molecules are blown from the Sun’s atmosphere by the solar winds through small openings in the magnetic fields to the Earth’s surface. As the Earth’s magnetic fields are weaker towards the poles, they are not able to deflect the electrons and they get their way to the Earth’s atmosphere and come into contact with elements on Earth. These impacts produce the aurora light referred to as the dancing lights of the north.
Aurora lights extend from 50 miles to as high as 400 miles above the surface of the Earth, and emit different colors based on the range of occurrence. The most vivid colors encompass a pale yellowish green color discharged by oxygen particles occurring 60 miles above the Earth’s surface. Unique red auroras are released by higher altitude oxygen particles above 200 miles and blue or purplish lights produced by nitrogen molecules above 300 miles.