T
Tom Wheeler
Guest
What causes the Northern and Southern Lights?
The famous Northern and Southern Lights -- Aurora Borealis and Aurora
Australis for those Latin lovers among us -- are caused by high-energy
particles from the Sun cascading down on Earth. As they near our planet,
they interact with Earth's magnetic field, which channels them toward
the north and south magnetic poles.
There they are accelerated downward, and at altitudes ranging from 90 to
700 km (50 to 450 miles), the particles collide with atoms of our upper
atmosphere, a process that results in a glowing field of excited gas.
These sheets of lights can take on many beautiful colors, and often
persist for hours on end, dancing gracefully in the polar skies.
Earth isn't the only planet that experiences aurorae; recent images from
the Galileo probe, in orbit around Jupiter, clearly show massive auroral
displays many times the size of Earth taking place high in the Jovian
atmosphere. As we study our fellow planets in ever-increasing detail, it
is all but certain that more such spectacular and eerily beautiful
scenes will be discovered.
Copyright 1995-2005 The University of Texas.
The famous Northern and Southern Lights -- Aurora Borealis and Aurora
Australis for those Latin lovers among us -- are caused by high-energy
particles from the Sun cascading down on Earth. As they near our planet,
they interact with Earth's magnetic field, which channels them toward
the north and south magnetic poles.
There they are accelerated downward, and at altitudes ranging from 90 to
700 km (50 to 450 miles), the particles collide with atoms of our upper
atmosphere, a process that results in a glowing field of excited gas.
These sheets of lights can take on many beautiful colors, and often
persist for hours on end, dancing gracefully in the polar skies.
Earth isn't the only planet that experiences aurorae; recent images from
the Galileo probe, in orbit around Jupiter, clearly show massive auroral
displays many times the size of Earth taking place high in the Jovian
atmosphere. As we study our fellow planets in ever-increasing detail, it
is all but certain that more such spectacular and eerily beautiful
scenes will be discovered.
Copyright 1995-2005 The University of Texas.
