Experts: Flares May Have Helped Planets

AP on Yahoo ^ | 5/10/05 | Alicia Chang - AP

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LOS ANGELES - Solar flares are infamous for wreaking havoc on electrical power lines and communication signals. But a team of astronomers says bursts emitted by the sun in its youth may have helped planets form.

Looking through NASA's Chandra X-ray Observatory, the astronomers focused on a cluster of young stars in the Orion Nebula, 1,500 light years from Earth. Studying 30 sun-like stars over two weeks, they found the young stars erupted in flares more powerful than those produced by the sun.

The observation could explain how Earth survived during its formative years, astronomers said.

Half the stars in Orion showed evidence for disks, places where rocky planets might be formed. Recent studies have shown that when X-ray flares strike planet-forming disks, they interact with the disk and affect the position of a planet from a star. The astronomers theorized that energetic flares prevent developing planets from falling into the newborn star.

"Big X-ray flares could lead to planetary systems like ours where Earth is a safe distance from the sun," astronomer Eric Feigelson of Penn State University said Tuesday. "Stars with smaller flares, on the other hand, might end up with Earth-like planets plummeting into the star."

Details will appear in a future issue of The Astrophysical Journal.

Christopher McKee, professor of physics and astronomy at the University of California, Berkeley, said the data collected by the Chandra telescope is a "treasure trove" that will help scientists in understanding planetary formation.

"It shows that the early evolution of the sun might have had significant effect on how the solar system formed," said McKee, who was not involved in the project.

Planets are believed to form when clouds of dust and rock become compacted under the force of gravity.

Solar flares are strong releases of energy that send protons, X-rays, electrons and other radiation streaming outward. In our solar system, such flares can sometimes cause magnetic storms on Earth by disrupting the Earth's magnetic field.

The Chandra telescope was carried into orbit by the space shuttle Columbia in 1999.

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On the Net:

Chandra X-ray Observatory: http://chandra.harvard.edu

Harvard-Smithsonian Center for Astrophysics: http://cfa-www.harvard.edu

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This undated image provided by NASA's Chandra X-ray Observatory shows a cluster of young stars in the Orion Nebula, 1,500 light years away from Earth. Studying 30 sun-like stars over two weeks, NASA found the young stars erupted in flares more powerful than those produced by the sun. The observation could explain how Earth survived during its formative years, astronomers said Tuesday, May 10, 2005. (AP Photo/NASA)