The Northern Lights The Aurora Borealis. The dancing lights in the cold northern sky has mystified...

Post on 24-Dec-2015

222 views 4 download

Tags:

transcript

The Northern Lights

TheAurora Borealis

The dancing lights in the cold northern sky has mystified and intrigued mankind for centuries.

They have been seen close to the north pole eerily glowing in green, blue and even in red.

They were named in 1621 by Pierre Gassendi after:

Aurora, the Roman Goddess of the Dawn,

and the Greek word for wind Boreas.

During the middle ages, the northern lights were believed to be a sign from God.

It wasn’t until 1741 when Olof Hiorter and Anders Celsius first described evidence for magnetic influence.

The Earth is constantly assaulted byparticles expelled by the Sun. However,

there are times when the amount ofparticles are significantly increased. As

in times of Solar Storms.

Solar Flares fire particles towardEarth at speeds of around

one million MPH.

When these particles reach Earth, they get caught in the magnetosphere, a teardrop-shaped area of highly charged

electrical and magnetic fields.

These particles then interact with our atmosphere creating breathtaking streams of color.

The color of the lights depend on what particle they interact withAnd how high above the surface they are.

Interaction with oxygen particles will producegreen and red, lights.

When nitrogen is involved the lights can be seen in blue and violet.

Since the Magnetosphere is connected to both the northAnd southern hemispheres, the particles also interact withThe south pole creating the Aurora Australis, the Southern

Lights.