Solar Eruption Hits Planet Earth

By Daniel Sorid Staff Writer posted: 09:00 am ET 13 June 2000

An ejection of high-energy particles from the sun hit Earth Monday afternoon, but surprised space weather forecasters with its lack of intensity.

Forecasters at the National Oceanic and Atmospheric Administrations (NOAA) Space Environment Center detected the eruption on June 10, and expected a powerful storm to hit Earth sometime Monday or Tuesday.

While the storm did hit Earth, at 6 p.m. Eastern Daylight Time (22:00 GMT) Monday, NOAAs forecasters said they do not expect the storm to cause any damage to satellite communications. Aurora watchers at high altitudes might have seen a show, however.

"It was a pretty good shock," said Dave Speich, a space weather forecaster at NOAA. But the disturbance was weaker than expected, he said. "At this stage, its not anything to write home about."

As of Tuesday morning, NOAA is not following any current solar storms. The sun is at the peak of its 11-year activity cycle, in which it erupts often with high-energy particles that can damage satellites and injure astronauts.

The eruptions, called coronal mass ejections (CMEs), are difficult to track as they travel through space. While sun watchers can see when the ejections happen, they often cannot accurately predict where the high-energy particles will go.

But a team of researchers at the University of California at San Diego (UCSD) and Japan's Nagoya University is trying a new technique: employing a network of four radio telescopes to infer where the solar eruptions will travel, potentially saving damage to equipment and even lives.

The team said it has improved the ability to predict the path of CMEs by detecting fluctuations, or scintillations, in natural radio signals.

"If you have four radio telescopes not too far apart, then you can correlate the time the scintillation pattern goes from one telescope to the other," said Bernard V. Jackson, a solar physicist at UCSD's Center for Astrophysics and Space Sciences, in a statement. "That allows you to say how fast the material is moving."

In December 2001, forecasts of solar eruptions will improve considerably, researchers say, with the launch of an Air Force satellite that will study the scattering of sunlight to predict the path of CMEs.

The satellite, called the Solar Mass Ejection Imager, will provide a much clearer picture of where solar ejections are going, Jackson said. "We'll get a thousand times more data," he said in the statement. "We'll be able to resolve these things by an order of magnitude better."

http://www.space.com/scienceastronomy/solarsystem/solar_eruption_000612.html

-- Martin Thompson (mthom1927@aol.com), June 14, 2000