Significance of backwards sunspots debated


  • Sarah Zielinski


The appearance within the past five weeks of two sunspots with ‘backwards’ magnetic polarity has scientists debating whether they are the first sunspots of the new solar cycle. An early start to cycle 24, originally predicted to begin in 2007, could indicate that it will be more active than the current one, said David Hathaway, a solar physicist at NASA's Marshall Space Flight Center.

Nearly all of the sunspots in a solar cycle have the same magnetic polarity, which alternates with each new cycle, but sunspots from each cycle can overlap for a year or two during the switch.The official beginning of a new cycle, however, is determined from monthly averages of sunspot activity; only months after a minimum in activity has occurred can scientists say that a new cycle has begun.