Mystery of the Sun
By Kathy Morrell
We marvel at the rosy glow of sunrise and the sparkle of light off a field of snow. We squint into the glare as we drive into the sunset. We beg for a blue sky after days of dreary rain. We take the Sun for granted and yet it is an awesome phenomenon and in so many ways, a mystery we have yet to explore.
The first solar mystery, one that James Edgar will discuss at the YFBTA Symposium, involves the Coronal Mass Ejection (CME). The CME is a massive outburst of solar wind and magnetic fields that rises above the solar corona. At times, these outbursts are projected into space, arriving as far as the earth’s atmosphere and continuing beyond. There is a direct correlation between a CME and the appearance of the aurora. However, predicting the auroraeis uncertain. Sometimes, a CME occurs, predictions are made and the sky dazzles us with a wild display of dancing greens, blues and reds. Other times, astronomers predict an awesome display of the aurora and they don’t appear. It’s all in the predicting – why do some outbursts result in aurorae, and others do not?
Which leads to a second mystery – how to predict the occurrence of the CMEs. Such knowledge is important because the solar wind with its load of charged particles and ions may cause significant damage to satellites and the power grid. For example, in March 1989, an outburst caused anomalies in weather satellite communications. Even the Space Shuttle Discovery was affected. At the same time, transformers blew across the province of Quebec, plunging some regions into darkness.
Clearly, there is a need to delve into the mystery of the Coronal Mass Ejection. In 1995, NASA and the European Space Agency launched a satellite called the Solar and Heliosphere Observatory (SOHO). Its goal was to explore the mystery, to try and predict these outbursts, to suggest solutions to prevent significant damage.
The third mystery involves sunspots, dark spots that appear on the surface of the sun. Astronomers have discovered that sunspots cycle in number over a period of abouteleven years. Within each cycle the number of sunspots will vary. Scientists suspectthat when there are few sunspots there will be lower than average temperatures here on Earth. For example, during the Maunder Minimum (1645 – 1715), there were very few sunspots and temperatures across Western Europe plummeted. Even the Thames River froze, allowing for fairs and royal parties on the ice.
The question is whether there is any correlation between sunspot activity and climate change. Scientists note that Cycle #25 should have already started, yet there is every indication that it has not. Is this a reason for the serious storms we have had over the past few decades? Astronomers don’t know but they wonder. The mystery deepens.
At the Symposium, James Edgar will help us explore the Sun and all its mysteries. Through his oral and video presentation, we will look at the facts, but more importantly, we will come to appreciate that we have much to learn.
Edgar’s interest in astronomy began in the early 1970s when he and his family went into the dark of night to see CometKohoutek. Unfortunately, it didn’t present itself at naked-eye brightness – hardly even visible in binoculars! He was disappointed. His children were, too. Ironically, from that missed sighting began his passion for astronomy.
Edgar started by volunteering with the Vancouver Museum, going into schools, talking to children about the Sun and the stars. In 1999, he bought his first telescope. One year later, his son bought him a membership in The Royal Astronomical Society of Canada (RASC) and as they say, the rest is history. Edgar has attended every General Assembly of the Society since 2001. He is passionate about passing on his interest in astronomy to everyone – adults and children alike. He is now National Secretary of the RASC, production manager of the Society’s bi-monthly Journal, and assistant editor of the RASC Observer’s Handbook.
The YFBTA is proud to announce that James Edgar will lead us skyward not to the stars but to the Sun, our awesome mysterious Sun.
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