"The solar wind, energetic particles and eruptions travel to Earth and cause a variety of effects," Thompson said. "We begin to feel these effects in as little as eight minutes."
She suggested it would be reasonable to assume "that everyone in this room has suffered a space weather effect," and said that cell-phone dropouts and radio problems could be symptoms of such an event.
"We have become increasingly dependent on technologies that are vulnerable to space weather effects," Thompson said.
Electric power plants, geostationary satellites, space flights and the broadcast of human speech are all susceptible to harmful space weather effects, according to Thompson.
Although the Sun is a relatively average star, it is "an extremely variable magnetic star" in terms of planet Earth, she said.
She cited sunspots and flares as events that can generate these space weather effects. Some high-energy particles take as few as 30 minutes to arrive on Earth, she said, explaining that a quarter of the planet's possible reaction time is lost by the time light arrives from the Sun and a change is detected.
"There is never a dull moment -- the Sun's always doing something," she said.
One of the issues in researching the Sun's magnetic phenomena and their effects on the Earth is gathering enough meaningful data, according to Thompson.
"We've only had five solar minima since space measurements became available," she said. "Accurate measurements of solar irradiance and solar wind energy inputs have only been available in recent decades. Some of these regimes haven't been covered as well as we hoped."
Thompson, who works at NASA's Goddard Space Flight Center in Greenbelt, Md., holds a B.A. in physics and mathematics from the University of Pennsylvania and a Ph.D. in physics from the University of Minnesota. Mary Hudson, a physics and astronomy professor at Dartmouth, introduced Thompson at the event.
"[Thompson] and I were both invited last year, along with two other scientists, to give talks at the National Air and Space Museum in Washington, D.C., in a monthly lecture series for the general public," Hudson said in an interview with The Dartmouth.
Hudson cited Thompson's lecture at the National Air and Space Museum -- where Hudson also spoke -- as well as the fact that Thompson has spoken before at Dartmouth, as reasons for inviting the physicist to speak at the College this year.
Tuesday's lecture was affiliated with NASA's Living With a Star program, whose goal is to "[understand] the changing Sun and its effects on the Solar System, life, and society," according to the program's web site.
The public lecture series is sponsored in part by the Pieter von Herrmann 1950 Fund in Physics and the Carol Berkowitz Fund in Physics.
"A couple of faculty members are appointed by the chair to find speakers who can come and speak at the public level," Judith Lowell, Dartmouth's physics and astronomy department administrator, said. "Anybody can attend -- it's not specific to the laymen, but we want to make sure that laymen can understand what's going on."
Louisa Gilder '00, author of "The Age of Entanglement: When Quantum Physics Was Reborn," will give the next lecture in the four-part series on November 20.
