When the sun erupts, sometimes we feel it on Earth

By Chris Oliver
Advertiser Staff Writer

A flare erupts from the sun, blasting radiation and particles out into space and making itself felt on Earth. Advertiser library photo • July 1, 2002 'Keeping Track of the Sun in Hawai'i' A lecture by Jeff Kuhn 7 p.m. tomorrow at the Institute for Astronomy Auditorium, 2680 Woodlawn Drive, Manoa. Free. Information: 956-6712.

"Big mistake," says Jeff Kuhn, a solar expert and associate director of the Institute for Astronomy with responsibility for Haleakala's Mees Solar Observatory.

"Last month's outburst of solar activity (the most turbulent in 30 years), triggered serious effects on Earth, knocking out two Japanese satellites and power on part of the Swedish power grid," Kuhn said. "It was unexpected, and highlights human confusion over how the sun works."

Kuhn will lecture tomorrow on "Keeping Track of the Sun in Hawai'i" and discuss why solar scientists believe the sun is a critical factor in changes on Earth, how the sun's behavior varies and what it could mean for us.

"Global warming is not due only to human production of greenhouse gases, but other causes as well," Kuhn said. "During the lecture, we'll look at how the sun is likely to be part of the problem. This last solar outburst shouldn't have any long-term effects on us, but then again, we don't know how or why the sun varies."

Kuhn said the large sunspots observed last month were about the size of Jupiter, 10 times the size of Earth; the part causing the flares is about the diameter of the Earth; and the entire solar storm came from a region bigger than the Earth.

Kuhn, who trained as a physicist, became fascinated by the sun: "We need to understand how it works in order to decide if gravity works the way we think it should," he said. "Solar research is one of perhaps only two astronomical research directions which have direct bearing on life here on the Earth."

And the other?

"Killer asteroids," said Kuhn. But that's another lecture.