Solar Rays Hit Space Age High

Cosmic Rays Hit Space Age High

 

Energetic iron nuclei counted by the Cosmic Ray Isotope Spectrometer on NASA's Advanced Composition Explorer (ACE) spacecraft reveal that cosmic ray levels have jumped 19% above the previous Space Age high.

 

An artist's concept of the heliosphere, a magnetic bubble that partially protects the solar system from cosmic rays.

 

"In 2009, cosmic ray intensities have increased 19% beyond anything we've seen in the past 50 years," says Richard Mewaldt of Caltech. "The increase is significant, and it could mean we need to re-think how much radiation shielding astronauts take with them on deep-space missions."

 

The cause of the surge is solar minimum, a deep lull in solar activity that began around 2007 and continues today. Researchers have long known that cosmic rays go up when solar activity goes down. Right now solar activity is as weak as it has been in modern times, setting the stage for what Mewaldt calls "a perfect storm of cosmic rays."

 

Full Story:

www.nasa.gov/topics/solarsystem/features/ray_surge.html

 

Credit: Richard Mewaldt/Caltech

Voyager solar system graphic: NASA/GSFC/Walt Feimer

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