Solar eclipse offers rare chance for experiments aimed at protecting satellites and power grids

Key Points
  • Solar flares and coronal mass ejections threaten spacecraft, GPS signals and radio waves.
  • Scientists think they have a new method for forecasting them.
  • The eclipse will offer a rare opportunity to test new equipment.
The third most-powerful solar flare ever observed in X-ray wavelengths erupted from Sunspot 486 early October 28, 2003, at approximately 6 a.m. Eastern Standard Time. A coronal mass ejection (CME) directed almost straight at Earth preceded the flare, sending electrically charged gas toward our planet, say NASA and European Space Agency (ESA) scientist.
NASA | Getty Images

While countless skygazers will be enjoying the beauty of the solar eclipse in late August, a team of scientists will be using the brief window to perform an experiment that could protect valuable technology from violent eruptions on the sun.

One group in particular is researching methods that may one day allow science to forecast solar flares and "coronal mass ejections," which can damage or disturb an ever-growing variety of technological devices in space and on Earth, from satellites and spacecraft to power grids.

These events are caused by the sun's magnetic field, which is generated by electrical currents inside the star. Every so often, these erupt in the form of phenomena such as a solar flare, which is usually described as a sudden and intense flash of brightness, or a coronal mass ejection, which is a blast of magnetic solar particles that erupts from the sun into space.

These phenomena are perfectly natural, but they can pose risks to technology. In 1989, for example, a coronal mass ejection hit Earth's own magnetic field and actually created electrical currents in the ground. One of these currents struck the power grid in the Canadian province of Quebec, knocking out power for about 12 hours. The solar flare also jammed signals from Radio Free Europe going into Russia, leading some to believe the Kremlin had blocked the signal.

"These things are not becoming more common on the sun, but the fact that these are impacting our lives more makes it important to understand them now," said Paul Bryans, a project scientist at the High Altitude Observatory at the National Center for Atmospheric Research and one of the researchers on the team.

Apart from radio signals, solar flares have also been shown to disrupt global positioning satellite signals and raise radiation levels in space, which could pose threats to astronauts.

"One big problem we have in solar physics is that we are very bad at predicting when these events will happen," said Bryans.

"The main reason we have such difficulty predicting them is, while we know it is all driven by the magnetic field, we don't have any way of measuring the coronal magnetic field," he said.

There are two main reasons for this: the coronal magnetic field is relatively weak, and it is usually obscured by the sheer brightness of the sun.

They intend to solve the second problem by taking their measurements during the upcoming eclipse, which by blocking the sun itself will give a much better view of the corona — the gas-filled outer atmosphere surrounding the sun.

The team will solve the first problem by looking at the infrared light emitted by the corona — which is particularly sensitive to measurement. Since the magnetic field shapes the direction of the infrared light, if they can determine the shape and direction of the light they can grasp the shape of the magnetic field.

So the researchers will set up a series of experiments on Casper Mountain in Wyoming on the day of the eclipse.

"The basic question we are trying to work on is: Can we measure the magnetism of the sun and find the places where energy is stored that causes space weather?" said Philip Judge, senior scientist at the observatory.

To do this, they will combine spectral measurements from an interferometer with images from an infrared camera to get an overall picture of the coronal infrared spectrum. Both of these are new experiments — no one has ever measured this particular slice of the infrared spectrum on the sun's corona before, and the team will be using the infrared camera for the first time.

They will then combine that information with images taken by another new device — a special polarizing camera, which can capture the way the corona's magnetic field polarizes the infrared light.

Once they can see how the light is polarized — the shape the light has and the directions it moves in — the team can infer the shape of the magnetic field.

If scientists are to forecast solar flares or coronal mass ejections, they will need to learn about the behavior of the electrical currents inside the sun that produce these eruptions.

"And once you know the magnetic field, you know the currents," Judge said. "If we can get the data about the magnetic field and watch it evolve in time in the corona, we would know much better when we could expect to see damage to spacecraft."

But this is the first step in a process that will likely span several years. "The two and a half minutes we get is not going to be enough to answer the question," Bryans said.

But if successful it will be a good start. They will be able to repeat the experiment during future eclipses and apply for funding to place the instruments on spacecraft, satellites or even airplanes, where data can be taken more frequently.

Since the research they are doing is so new, they need to demonstrate it has some potential before NASA or another entity shoulders the significant costs associated with flying similar equipment into space.

"The eclipse gives you the chance to do this stuff on the cheap," Bryans said, "because the moon is doing all the work for you."

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