Lisa Kewley studied cosmic rays and gamma-ray bursts.
There's a considerable (overlapping) range of frequencies for both gamma rays and cosmic rays, but the upper reach for gamma rays is considered to be higher than that for cosmic rays, all the way to 10^30Hz.
Cosmic rays were discovered by Victor Hess in 1912.
the answer is gamma rays
Any energetic event can produce cosmic rays, ranging from supernovae events to quasar jets.
Gamma rays are a form of electromagnetic radiation, and they are the highest frequency form of that type of energy. They can be said to vibrate fastest. But cosmic rays are mostly protons, which are a form of particulate radiation. Comparing gamma rays to cosmic rays as regards frequency is not something we do.
Cosmic rays can enter Earth through Mars because Mars has a thinner atmosphere than Earth, allowing cosmic rays to penetrate more easily. The lack of a strong magnetic field on Mars also means there is less protection against cosmic rays compared to Earth. This makes Mars a potential gateway for cosmic rays to reach Earth.
The GZK cutoff is significant in the study of cosmic rays because it sets a limit on the energy levels of cosmic rays that can travel long distances in space without losing energy. This cutoff helps scientists understand the origins and properties of cosmic rays and provides insights into the nature of the universe.
Secondary cosmic rays are the product of collisions with primary cosmic rays. Primary ones are the kind that arrive from space and hit earth - typically air molecules in the upper atmosphere, which creates (and transfers its energy to) other particles, often creating a shower ('air shower') of secondary particles, also of high energy. Even though these products are results of collisions from within the Earth's atmosphere, they are still referred to as cosmic rays, although given the name "Secondary" cosmic rays. Note that secondary cosmic rays' composition or relative composition can differ from the cosmic rays arriving from space; particularly as new particles like muons and pions can be generated.
V. S. Murzin has written: 'Cosmic rays and their interactions' -- subject(s): Cosmic rays
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yes