Jul 30, 2008

Mystery of Northern Lights Solved?

Scientists at NASA have uncovered the mystery behind the spectacular northern lights or aurora borealis. It is the magnetic explosions about one-third of the way to the moon that powers geomagnetic storms and causes the northern lights. Five THEMIS (Time History of Events and Macroscale Interactions during Substorms) satellites of NASA have uncovered this secret.

How the scientists confirmed this theory? The five small THEMIS satellites observed the beginning of a geomagnetic storm in February and the ground observatories in Canada and Alaska recorded the brightening of the northern lights. The storm was triggered by a phenomenon known as magnetic reconnection at about 80,000 miles from Earth. The southern lights or aurora australis also brightened and darted across the sky at the same time.

What is magnetic reconnection? Earth's magnetic field lines are regularly stretched like rubber bands by the solar energy. But, suddenly these lines snaps and thrown back to Earth and it reconnects. This sudden change creates a short circuit and causes a burst of light and movement near the northern and southern poles. That's why we see the spectacular shapes and colors, that dances across the sky.

Scientists hopes that these findings will help in further research of the geomagnetic storms that can harm astronauts in orbit and disrupt power and communications on Earth. Well, want to see the northern lights? Take a look at this time lapse video of northern lights recorded in British Columbia, Canada..


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