How deadly are cosmic rays ?

http://www.unexplained-mysteries.com/images/newsitems/earth2.jpg Cosmic rays constantly bombard the Earth with high-energy particles and for the most part we do not notice them but some scientists believe that these rays may have played an important role in the evolution of life on the planet."Cosmic rays pour down on Earth like a constant rain. We don't much notice these high-energy particles, but they may have played a role in the evolution of life on our planet. " View: Full Article | Source: Space.com Well, I think they should study more about these high energy rays and the secondary parti... [More]

Fantastic Four anyone??

So the people who know say that most cosmic rays collide with molecules in the upper atmosphere and create other forms of radiation. Doesn't that put the lie to all those people who were saying that it is the magnetic field which is keeping out the cosmic rays? Even without a magnetic field we would not have cosmic rays to fear. Similarly, wouldn't even a thin layer of metal protect from this out in space? If all they are is highly energized protons? I thought I had heard that many cosmic rays were left over from the Big Bang. The article seems to infer they are mostly made by super-novae. htt... [More]

Doesn't that put the lie to all those people who were saying that it is the magnetic field which is keeping out the cosmic rays? No one says that. The magnetic field protects us for charged particles (alpha and beta radiation) often from the sun. Cosmic rays are electromagnetic in nature (like light and heat) and are unaffected by magnetic fields.

Actually, cosmic rays are atomic nuclei boosted to obscene velocities by supernovas and interstellar magnetic fields. They are moving so fast and have a high enough mass that the earth's magnetic field does not really affect them, and the atmosphere is our main screen against them. The magnetic field mostly protects from particle radiation from the sun. Electrons and protons and helium nuclei. Electromagnetic radiation of a shorter wavelength than ultraviolet light is essentially totally masked by our atmosphere - though if a huge xray burst were aimed at our planet in the process of screening... [More]