View Article

view the latest news articles
Cosmic rays increase as sun hits solar minimum by Emma Woollacott
Wednesday, September 30th 2009, 10:10 AM EDT
Co2sceptic (Site Admin)
Watch out, space travelers: galactic cosmic rays have hit their highestt levels since the space age began.

"In 2009, cosmic ray intensities have increased 19 percent 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 rethink how much radiation shielding astronauts take with them on deep-space missions."

Image Attachment


Article continues below this advert:

The reason is the solar minimum, a deep lull in solar activity: cosmic rays increase as solar activity declines. Right now solar activity is as weak as it has ever been in modern times.

Galactic cosmic rays are subatomic particles - mainly protons but also some heavy nuclei - accelerated to near light speed by distant supernova explosions. They cause 'air showers' of secondary particles when they hit Earth's atmosphere. They're a health hazard to astronauts, and a single cosmic ray can disable a satellite if it hits an unlucky integrated circuit.

The sun's magnetic field - the heliosphere - is our first line of defense, scattering and deflecting the rays. The solar wind enhances this effect.

Image Attachment

"At times of low solar activity, this natural shielding is weakened, and more cosmic rays are able to reach the inner solar system," explains Dean Pesnell of the Goddard Space Flight Center.

Right now, the sun's magnetic field is weak, and solar wind pressure is at a 50-year low. If trends continue, says Dean Pesnell of the Goddard Space Flight Center, "We could see cosmic ray fluxes jump all the way to 30 percent above previous Space Age highs," predicts Mewaldt.

Earth is in no great peril from the extra cosmic rays. The planet's atmosphere and magnetic field combine to form a formidable shield against space radiation, protecting humans on the surface. Indeed, we've weathered storms much worse than this. Hundreds of years ago, polar ice cores show, cosmic ray fluxes were at least 200 percent higher than they are now.

"The space era has so far experienced a time of relatively low cosmic ray activity," says Mewaldt. "We may now be returning to levels typical of past centuries."
Source Link: tgdaily.com
Articles by Climate Realists and Topics

» Recently used highlighted

ALL #-E F-J K-O P-T U-Z
Useful links
Disclaimer
  • » News articles may contain quotes, these are copyright to the respective publication which will be stated, along with a link to the source article where available.
  • » If you feel your copyright has been violated please contact us and the article will be removed or amended at your request.
Site Details
  • » Launched 15 May 2009
  • » Website Design by Mr Zippy
Climate Depot Feed
  • » Feed Error