Monday, September 29, 2008

Smooth Salin': A Tranquil Solar Wind


The solar wind isn't blowing the way it used to. In fact, cosmic gale is at its lowest in 50 years, according to recent predictions made by solar physicists at NASA headquarters. The prediction comes after an analysis of eighteen years of data from the Ulysses satellite, the first satellite to study the regions of space above and below the sun's poles and take samples of the solar wind and solar magnetic field.

Originating from the sun's torrid outer atmosphere or corona, the solar wind is made up of streams of charged particles ( electrons and protons), blowing off the sun at high speeds in all directions, like a permanent gust of wind blowing streams of leaves off a giant tree. Interactions among streams of particles cause changes in speed and direction as they move away from the sun.

Scientists say the solar wind is blowing about 20-25% less hard than it was 10-15 years ago, during the last solar minimum or period of least solar activity in the sun's solar cycle, and lower than any observations since solar wind tracking began in the 1960s.

Taking into account the grand spectrum of the sun's 4.5 billion year history, researchers still aren't sure how uncommon a weakening of the solar wind is. It's possible that even lower winds occurred hundreds or millions of years ago, but of course the data just isn't available.

The lack of solar wind is causing cosmic rays to enter the Earth's atmosphere in greater numbers. While the earth has a protective shield to reduce the ray's intensity, they can damage satellite electronics and may harm astronauts by increasing space radiation.

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