Space: Mysterious Origin of Cosmic Rays Pinned Down

[bystander]

Mysterious Origin of Cosmic Rays Pinned Down
Space.com - 2010 Feb 15

Superfast protons sometimes slam into the Earth from space flying at close to the speed of light.

Where these particles, called cosmic rays, come from has been a scientific mystery. But new evidence helps confirm the leading explanation – that they originate in the distant remnants of dead stars.

Such a so called supernova remnants contains shells of gas that were ejected from a star before it collapsed in a supernova explosion. They harbor strong magnetic fields that are thought to behave like giant particle accelerators, speeding up particles that become cosmic rays.

[bystander]

NASA's Fermi Closes on Source of Cosmic Rays

New images from NASA's Fermi Gamma-ray Space Telescope show where supernova remnants emit radiation a billion times more energetic than visible light. The images bring astronomers a step closer to understanding the source of some of the universe's most energetic particles -- cosmic rays.

Cosmic rays consist mainly of protons that move through space at nearly the speed of light. In their journey across the galaxy, the particles are deflected by magnetic fields. This scrambles their paths and masks their origins.