Pop star: scientists predict sun explosions using 3-D images

Science World, Sept 3, 2007 by Andrew Klein

Put on a pair of 3-D glasses and check out this latest snapshot of the sun! That's what scientists at the National Aeronautics and Space Administration (NASA) are doing to learn more about Earth's nearest star.

Although the sun looks like a barely changing disk of light in our daytime sky, it's actually superactive. The violent bah of glowing gas produces the largest explosions in the solar system--called coronal mass ejections, or CMEs. CMEs can pack a punch equal to a billion megaton nuclear bombs. When blasts that powerful head our way, they can spell trouble on Earth.

FORECASTING BLASTS

To better predict CMEs, NASA scientists needed a closer look at the sun. So in 2006, they launched two spacecraft with special cameras onboard. They positioned the crafts so that one is ahead of Earth in its orbit, of path around the sun, and the other is behind. This placement has enabled the cameras to capture images in three dimensions. How? The distance between the two spacecraft is similar to the slight offset between your eyes, which gives you depth perception. This past spring, the crafts beamed back to Earth the first-ever 3-D snapshots of the sun.

By studying the images, scientists have been able to learn more about interactions between sunspots, or relatively cool, concentrated magnetic fields in the sun where CMEs originate. "In 3-D, we can see the magnetic fields in the sunspots," says Mike Kaiser, a NASA scientist working on the mission, dubbed Solar Terrestrial Relations Observatory (STEREO). "They look like twisting rubber bands," he says. If you keep twisting a rubber band, a knot will eventually pop up. The same is true for sunspots. That "pop" blasts a fierce shot of energy into space as a CME.

WARNING: DANGER!

Even though the sun is a distant 150 million kilometers (93 million miles) from our planet, it doesn't take long for the high-energy radioactive waves and particles from CMEs to reach Earth. In fact, it takes just one to three days.

That energy has the ability to disrupt satellite and radio communications. And that can cause everything from cell phones to airplane communication and electrical power-grids to fail. The radiation from a CME is also a serious hazard for astronauts working outside their spaceship. "If we can learn how to predict CMEs, we can warn pilots of radio interference and tell astronauts to shield themselves from harmful radiation in space," says Kaiser.

MAKE YOUR OWN 3-D GLASSES!

1) Trace the outline of the glasses below onto a sheet of 11-by-17-inch white paper. 2) Cut out your tracing, including the eyeholes. 3) Cut clear plastic report covers (of transparencies) so they are just large enough to cover each eyehole. Tape them to the glasses to make "lenses." 4) Using permanent markers, color one lens blue and one lens red. 5) Fold the glasses where shown on the figure below. Put on the glasses, with the blue lens over your left eye and the red lens over your right eye.

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Visit this NASA Web site to learn about different ways to view 3-D images: http://stereo.gsfc.nasa.gov/classroom/how.shtml