Volume 4, Number 3 July/August 1996
The ground does not shake, the sky does not turn black and the winds do not roar when a solar flare strikes the Earth. In fact, you could be standing outside looking up and never know you were being pelted with particles streaming in from 93 million miles away.
While a solar storm is invisible except for the ghostly auroras it creates, the danger it poses is very real. Huge power blackouts, blown-up transformers, melted conductors and failures in sensitive communications satellites are just a few of a storm's possible effects. Because solar disturbances attack the very foundation of our high-tech society, scientists are excited to find that satellite data will help them predict the onslaught of explosions on the Sun.
Researchers made the discovery using the Japanese/U.S. Soft X-ray Telescope aboard the Yohkoh spacecraft. The findings were presented in February 1996 during an international conference on solar storms held at NASA's Jet Propulsion Laboratory (JPL) and sponsored by the American Geophysical Union and the National Science Foundation.
Bruce Tsurutani, a senior research scientist at JPL, explained that researchers using the Yohkoh telescope see a sudden darkening of the Sun's usually bright x-ray corona just before a huge explosion sends tons of charged particles hurtling through the Solar System. Because it takes two to three days for this mass to reach the Earth's magnetic field, being able to spot the darkening means engineers would have time to protect the North American power grid and any threatened satellites.
"We have to work now on improving our ability to recognize these events," said John Kappenman of Minnesota Power. Kappenman sees the discovery as a quantum improvement over current prediction methods. "This is as significant as weather satellites when they were first deployed," he said.
In the upcoming year, the Sun will be closely monitored for advance warning of solar releases. "Satellites will give us highly reliable advance notice," Kappenman said. "We'll get at least an hour and possibly a couple of days."
This will help engineers prevent blackouts, such as the one a few years ago that started in Quebec and almost spread to the mid-Atlantic. "That was a close call," Kappenman said. "Couple blackouts with severe weather and you get life-threatening situations."
North America is most affected by solar storms because we are closest to the magnetic north pole and our power grid extends into the high latitudes. As with hurricanes and earthquakes, solar storms will probably always cause destruction. "You can help control the damage if you know they're coming," Kappenman said.
JPL built part of the Yohkoh telescope. NASA's program to study solar storm activities and their impact on Earth is called the NASA International Solar Terrestrial Physics Program, which is sponsored by the Office of Space Science with international partners, the European Space Agency and the National Space Development Agency of Japan.
For more information, contact Diane Ainsworth at the Jet Propulsion Laboratory.
Phone: 818/354-5011.
Please mention that you read about it in Innovation.
Curator: Joe Goldfus
