THE SUN appears to have started its next cycle of sunspots two years ahead of schedule, heralding a period of solar magnetic storms that could trigger radio interference and auroras in the night sky.
Sunspots generally wax and wane over an 11-year cycle. The current cycle still has about two years left to run, but astrophysicists at Caltech identified the first sunspot of the new cycle on 12 August.
The astrophysicists knew what it was because the spot鈥檚 magnetic polarity is the reverse of the previous sunspots, says Hal Zirin, director of Caltech鈥檚 Big Bear Solar Observatory. Such a magnetic flip is one of the hallmarks of the start of a new cycle, he says.
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If the cycle continues to run ahead of time, it would hit its maximum about 1999, rather than 2001. Magnetic eruptions known as solar flares, which can disrupt power lines and interfere with aeroplane navigation, are more frequent during the sunspot maximum.
