March 1, 2007—Twin NASA spacecraft studying the sun have beamed their spectacular first images to Earth, helping scientists to detect and track solar storms that can fry satellites, harm astronauts, and overload power lines.

The panoramic images, released today, were taken by a suite of five telescopes on the Solar Terrestrial Relations Observatory (STEREO) spacecraft, which were launched on October 25, 2006.

The pictures provide a closeup view of the sun's activity, such as this snapshot of loops in a magnetically active region that soon afterward produced a series of intense flares (top). The images also provide a progressive view of the sun's radiation all the way to Earth's atmosphere (bottom).

Scientists say this new sweeping viewpoint will let them study the flow of energy from the sun to Earth, especially coronal mass ejections—violent eruptions of electrically charged gas from the sun's atmosphere that can cause dangerous solar storms.

"The new view from the STEREO spacecraft will greatly improve our ability to forecast the arrival time of severe space weather," Russell Howard, principal investigator of STEREO's telescope suites, said in a statement.

"Previous imagery did not show the front of a solar disturbance as it traveled toward Earth, so we had to make estimates of when the storm would arrive. These estimates were uncertain by a day or so. With STEREO, we can track the front from the sun all the way to Earth, and forecast its arrival within a couple hours."

The best is still to come, NASA experts add. When the two STEREO craft reach their final positions—one slightly behind Earth, the other in front—they'll be able to provide stereo vision of the sun, in the same way our two eyes give us depth perception.

Full 3-D images of the sun and its storms are expected in April.

—Aalok Mehta

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