Auroras

1. Auroras By Rose Culliney

2. General Info • Auroras typically appear in the Ionosphere • They usually appear as a glow or as curtains • The Latin words Aurora borealis are roughly translated as ‘northern lights’. • The colors of auroras are red, blue, violet, and green; green is the dominant color • The aurora borealis is also known as the northern lights. • The northern lights are most active in the few hours before and after midnight.

3. General Info (cont.) • ‘Aurora’ is the name given to the roman goddess of dawn. • The aurora borealis is not effected by changes in the temperature of the Earth. • The aurora does not effect airplanes as they fly at altitudes well below the lights.

4. Auroras in the Solar System • Jupiter and Saturn also have auroras, the planets Uranus and Neptune have also been observed to have auroras as well. They have also have been observed on Venus and Mars. • Jupiter’s moons, especially Io, also have auroras.

5. What are the Northern Lights? • Aurora borealis means dawn of the north. • Most of them appear only in the far north. • They are most often seen in the auroral zone, an imaginary oval on top of the globe. • The farther south you are from the auroral zone, the less likely you are to see them. • Even though you usually see them far up north, if the conditions are just right you can see them farther south.

6. What are the Northern Lights? (cont.) • On very rare occasions, people in Mexico can see them. • The southern lights are called Aurora australis. • Together the northern and southern lights are called the polar auroras. • The lower edges of the lights are 60 miles above the earth, they are 10 times higher than most planes fly.

7. What are the Northern Lights? (cont.) • In Lapland, which is a region of northern Europe, the lights are called guovsahas, which means ‘light that can be heard’. • Some say the noise gets louder as the lights move.

8. What causes the Northern Lights? • Three things are needed for the northern lights: 1.) moving, charged particles 2.) a magnetic field 3.) an atmosphere. • The surface of the sun is extremely hot, the fiery corona that surrounds it is even hotter. The atoms break apart and the particles fly everywhere. It is called solar wind. When those particles reach the earth’s atmosphere, the northern lights form.

9. What causes the Northern Lights? (cont.) • The center of the auroral oval is Greenland. • When facing the earth, solar flares make the auroras shine even brighter.

10. Danger Signs • During northern light shows, power and communication signals can fail. • Earth’s magnetic field changes when the light appears, so compasses can be unreliable. • They produce electrical currents that can corrode oil and natural gas lines. • Even satellites circling above earth can be affected.

11. Danger Signs (cont.) • In 1989, the sunspot cycle was at its peak; it caused auroras to be very bright and caused a blackout in Quebec, Canada. At 2:45 am streetlights went out, and radios and televisions stopped working. • Just a few months after the blackout, a gas pipeline exploded near the Trans-Siberian Railroad. Two passenger trains were set ablaze; more than a thousand people were rescued, but five hundred people died.