Did you know?
- Earth isn’t the only planet with aurora. Jupiter and Saturn have auroral ovals on both hemispheres. Astronomers have also spotted aurora on Uranus and Neptune.
- Unlike the curtains of colourful light that appear on Earth, the aurora on Uranus look like faint glowing dots.
- Despite not having a magnetic field, astronomers have noted an aurora-like phenomenon on Venus caused by the reaction between the solar wind and the ions in the planet’s ionosphere.
- The Earth’s magnetic field extends thousands of kilometres into space.
- A coronal mass ejection, or an ejection of energetic plasma from the Sun, can travel at speeds of up to 10 million kilometres per hour.
- Major solar storms can cause power outages, such as the 1989 blackout in Quebec. In March 1989, an explosion on the sun was so powerful it was like thousands of nuclear bombs exploding at the same time. Quebec lost power for 12 hours.
- During the 1989 geomagnetic storm, the northern lights could be seen as far south as Florida and Cuba.
- Aircraft crews on transpolar flights and astronauts experience higher doses of radiation during periods of intense solar activity.
- Astronauts on board the International Space Station are at the same altitude as the auroras and see them from the side.
Scientists in Canada have been studying the northern lights for more than 170 years.
- Canada’s first magnetic observatory, the Toronto Magnetic and Meteorological Observatory, was established in 1839 and is the oldest scientific institution in Canada. In 1852 its founder, Sir Edward Sabine, determined that magnetic disturbances are related to the appearance and extent of sunspots (cooler, highly magnetically-active areas on the sun’s surface).
- Edmund Halley first proposed that the northern lights formed according to the Earth’s magnetic field in 1716.
- Canada’s Ultra-Violet Auroral Imager (UVAI) launched into orbit with Sweden’s Viking satellite in 1986. It provided Canadian scientists with their first photographs of the entire aurora region.
- The colours of the aurora are determined by the type of molecules with which solar wind particles collide as they enter the earth’s atmosphere. Solar wind particles and oxygen molecules produce green and yellow light, while nitrogen molecules produce red, violet and blue light.
- Auroras in the southern hemisphere are called aurora australis.
- The aurora borealis is named after the Roman goddess of the dawn, Aurora, and the Greek term for “wind of the north,” boreas.
- Inuit used to fear the northern lights, believing that the phenomenon could decapitate people who travelled at night by dogsled. It was also thought that cutting the sled dogs’ ears provided protection from these attacks.
Sources: Canadian Space Agency, NASA, Discovery News, PhysOrg.com, Nunavik Tourism