Cosmic rays ( Shower of energy )

Cosmic rays are extremely high energy particles mainly coming from the outside of our solar system , they primarily composed of high energy protons and an atomic nuclei they could produce showers of secondary particles that penetrate and interact with the Earth atmosphere

Secondary particles formation 

As I said before that cosmic rays forms primarily form high energy protons and an atomic nuclei to understand the formation of secondary particles let's take a look at this image  

an atomic nuclei and how it forms a secondary particles by interacting with the Earth's atmosphere

Now let's take a  look at an image of proton interaction with Earth's atmosphere and how it forms secondary particles

Cosmic rays and the atmospheric chemistry

Cosmic rays affects the chemistry of the Earth's atmosphere it is responsible for continuous formation of a number of unstable isotopes such as Carbon-14 from via reaction 

n + ¹⁴N → p + ¹⁴C
cosmic rays kept the level of Carbon-14 roughly constant {70} tons for the last 100,000 years 
Cosmic rays also ionizes the oxygen and nitrogen which lead to a number of reactions and one of these reactions results in ozone depletion 
Sources of cosmic rays

 There are a wide variety of cosmic rays sources began to appear such as Supernova
Quasars , Active galactic nuclei , Hypernova  and Black holes