Scream Aurora Borealis
Panorama of the most spectacular northern light at place Bogøy in the commune Steigen, province Nordland northern Norway.
More northern light pictures: Norway arctic photography
The northern lights, one of several astronomical phenomena called polar lights (aurora polaris), are shafts or curtains of colored light visible on occasion in the night sky.
Polar lights (aurora polaris) are a natural phenomenon found in both the northern and southern hemispheres that can be truly awe inspiring. Northern lights are also called by their scientific name, aurora borealis, and southern lights are called aurora australis.
Sten Odenwald, author of The 23rd Cycle: learning to live with a stormy star (New York, Columbia University Press, c2001), provides insight into how northern lights are generated:
The origin of the aurora begins on the surface of the sun when solar activity ejects a cloud of gas. Scientists call this a coronal mass ejection (CME). If one of these reaches earth, taking about 2 to 3 days, it collides with the Earth’s magnetic field. This field is invisible, and if you could see its shape, it would make Earth look like a comet with a long magnetic ‘tail’ stretching a million miles behind Earth in the opposite direction of the sun.
When a coronal mass ejection collides with the magnetic field, it causes complex changes to happen to the magnetic tail region. These changes generate currents of charged particles, which then flow along lines of magnetic force into the Polar Regions. These particles are boosted in energy in Earth’s upper atmosphere, and when they collide with oxygen and nitrogen atoms, they produce dazzling auroral light.
Odenwald further tells us “Aurora are beautiful, but the invisible flows of particles and magnetism that go on at the same time can damage our electrical power grid and satellites operating in space. This is why scientists are so keen to understand the physics of aurora and solar storms, so we can predict when our technologies may be affected.”
Fun Facts about northern lights
- According to Neil Bone (The Aurora: sun-earth interactions, 1996), the term aurora borealis–northern dawn–is jointly credited to have first been used by Pierre Gassendi (1592-1655) and Galileo Galilei (1564-1642), who both witnessed a light display on Sept. 12, 1621. However, Bone also includes a description of the northern lights made 1,000 years prior by Gregory of Tours (538-594.) It included the phrase, “… so bright that you might have thought that day was about to dawn.”
- Auroras have been observed since ancient times.
- The height of the displays can occur up to 1000 km (620 miles), although most are between 80-120 km.
- Auroras tend to be more frequent and spectacular during high solar sunspot activity, which cycles over approximately eleven years.
- Some displays are particularly spectacular and widespread and have been highlighted in news accounts. Examples include auroral storms of August-September, 1859, Feb 11, 1958, (lights 1250 miles wide circled the Arctic from Oregon to New Hampshire) and March 13, 1989, (the whole sky turned a vivid red and the aurora was seen in Europe and North America as far south as Cuba).
- Legends abound in northern cultures to explain the northern lights. Some North American Inuit call the aurora aqsarniit (“football players”) and say the spirits of the dead are playing football with the head of a walrus. Often legends warn children that the lights might come down and snatch them away.
- June 1896, Norwegian Kristian Birkeland, the “father of modern auroral science,” suggested the theory that electrons from sunspots triggered auroras.
- Yellowknife (Northwest Territories, Canada) is the capital for aurora tourism.
- The earliest known account of northern lights appears to be from a Babylonian clay tablet from observations made by the official astronomers of King Nebuchadnezzar II, 568/567 BC.
- Some people claim to hear noises associated with the northern lights, but documenting this phenomenon has been difficult.