What's Wrong with the Sun?

• "Something appears to have changed inside the sun, something the models did not predict. But what?"


• "These findings have thrown our best computer models of the sun into disarray."


• "high solar activity has a disproportionate warming influence on northern Europe"


• "The ultraviolet is varying much, much, much more than we expected"


• "The heat input into the stratosphere is much more variable than we thought"


• "solar activity is just one natural source of climate variability."

(NewScientist) SUNSPOTS come and go, but recently they have mostly gone. For centuries, astronomers have recorded when these dark blemishes on the solar surface emerge, only for them to fade away again after a few days, weeks or months. Thanks to their efforts, we know that sunspot numbers ebb and flow in cycles lasting about 11 years.

But for the past two years, the sunspots have mostly been missing. Their absence, the most prolonged for nearly a hundred years, has taken even seasoned sun watchers by surprise. "This is solar behaviour we haven't seen in living memory," says David Hathaway, a physicist at NASA's Marshall Space Flight Center in Huntsville, Alabama.

The sun is under scrutiny as never before thanks to an armada of space telescopes. The results they beam back are portraying our nearest star, and its influence on Earth, in a new light. Sunspots and other clues indicate that the sun's magnetic activity is diminishing, and that the sun may even be shrinking. Together the results hint that something profound is happening inside the sun. The big question is what? Read more