Canadian photographer Richard Gottardo recently spent 7 hours in Southern Alberta, capturing the remarkable color changes displayed by the northern lights, or the aurora borealis, which were seen over the Rocky Mountains.
The aurorae, from the Latin word for “sunrise,” and also the name of the Roman goddess of dawn, is a natural light display in the sky that can be viewed particularly in the high-latitude Arctic and Antarctic regions. The aurora borealis, or aurora australis, as it is known in the southern hemisphere, is caused by the collision of charged particles with atoms in the high altitude atmosphere, also called the thermosphere.
Below is Gottardo’s clip:
The colliding particles, which originate in the magnetosphere, are directed by the Earth’s magnetic field into the atmosphere. Most aurorae occur in a small band known as the auroral zone, which is typically 3° to 6° in latitudinal extent, and at all local times or longitudes. The auroral zone is typically 10° to 20° from the magnetic pole, which is defined by the axis of the Earth’s magnetic dipole. Although, during a geomagnetic storm, the auroral zone expands to lower latitudes.
Below is a clip of the aurora australis, captured by the crew of Expedition 29, on board the International Space Station. The shots were taken on September 17, 2011, during an ascending pass from south of Madagascar to just north of Australia, over the Indian Ocean:
The aurora borealis most often occurs near the equinoxes. The northern lights have had a number of names throughout history. The Cree Native American tribe of Canada call this phenomenon the “Dance of the Spirits,” an in Medieval Europe, the aurorae were commonly seen to be a sign from God.
Human persistence of vision allows the playback of roughly 24 pictures per second, in succession, to resemble what can be perceived as being normal motion. The more images inserted into a one second timeline, also called overcranking, the “slower” the scene will appear upon playback. Time-lapse photography, on the other hand, is an extreme form of undercranking, to where a very small amount of frames are run together, producing an illusion of fast motion upon normal playback.
Image via YouTube.
