Suns Power Hits New Low, May Endanger Earth?
That translates into a shrinking of the heliosphere, the invisible “bubble” of solar wind that extends beyond Pluto and guards the planets—ours included—from bombardment by cosmic rays. Speaking yesterday at a NASA teleconference, scientists refused to draw conclusions from their observations, especially with respect to whether the changes are influencing Earth’s climate. “That area of science is in the realm of speculation at this point,” said Nancy Crooker, a researcher at Boston University. But David J. McComas of the Southwest Research Institute, who leads one of the experiments onboard Ulysses, called the changes “significant.” “This is a whole-sun phenomenon. The entire sun is blowing significantly less hard than it was 10 to 15 years ago,” he said. “Over the entire record of sun observations, this is the longest prolonged low pressure that we’ve observed.” Variable Star Some variance in solar activity is normal for the sun, which has a 22-year magnetic cycle and an 11-year sunsp
