Accessibility links

NASA Issues First 3 D Images of Sun


The U.S. space agency NASA has released the first three dimensional pictures of the sun. It says the new view will greatly help scientists understand solar storms that can disrupt communications and power systems on Earth. VOA's David McAlary reports.

The new 3-D images came from twin NASA spacecraft named STEREO, launched last October. They are orbiting the sun, one slightly ahead of Earth and the other slightly behind, gradually separating from each other until they are 500,000 kilometers apart. The separation provides a three dimensional view of the sun, just as the offset in our eyes gives us depth perception.

Until the advent of this identical pair of observatories, images from Earth telescopes or orbiting solar telescopes were two dimensional. NASA solar scientist Madhulika Guhathakurta says the three dimensional images will help scientists determine where matter and energy flow in the sun's atmosphere much more precisely.

"We have to move away from the traditional sun-Earth line to view the sun from around, from over the poles, from under the poles to really get a deeper understanding of what is inside the sun, what is coming out of its surface, how is it affecting the entire solar system that we live in," said Madhulika Guhathakurta.

The main STEREO project scientist, Michael Kaiser, says the satellites' depth perception will help improve space weather forecasts.

Of particular concern are powerful eruptions of billions of tons of electrically charged gas that smash into Earth's magnetic field at millions of kilometers per hour. Such a shock wave can cause magnetic storms that overload electrical equipment and radiation storms that endanger spacecraft and unshielded astronauts.

Kaiser says the twin spacecraft can observe the shape and position of magnetic loops in active regions of the sun that generate the showers of hot gas.

"Those active regions have all these little, tiny loops inside," said Michael Kaiser. "What the loops are the magnetic field of the sun. Somehow these magnetic fields get twisted and can break apart, releasing this hot gas, and that is how you get a solar storm. What we want to do with STEREO is to study these loops in more detail to understand why certain ones break."

Unlike other solar observatories, STEREO can trace the sun's radiation blasts all the way back to Earth. Kaiser says this will help improve the accuracy of predictions about their severity and shorten estimates of their arrival time from half a day down to a few hours. This will allow operators of electrical utilities and satellites to take precautions to minimize damage.

"The sun, as you might guess, has been giving off solar storms for billions of years, and nobody much cared until recently," he said. "But now all of a sudden we are into this technological world, so we really need to know more about solar storms."

STEREO is an international project. Its cameras and particle detecting instruments were designed and built in the United States and Europe.

XS
SM
MD
LG