Cosmic Rays (Shannon)

What is a cosmic ray?

Cosmic rays are high energy particles that come from outer space. They are made mostly of the nuclei of atoms but also contain electrons, positrons, neutrinos, and other subatomic particles. Cosmic rays travel near the speed of light and have enough energy to send a proton anywhere from 43% to 99.6% the speed of light.

Types of Cosmic Rays

Galactic Cosmic Rays

The most common type of cosmic ray, galactic cosmic rays come from outside our galaxy. They are made of particles accelerated from the blast waves of supernova explosions.

Solar Energy Particles

Solar energy particles are nuclei and electrons accelerated due to activity on the surface of the sun.

Very-high Energy Cosmic Rays

When high energy cosmic rays collide with atoms in the upper atmosphere, pions are created. Those pions then decay into muons, neutrinos and cosmic rays. Those muons then further decay into electrons and positrons.

Anomalous Cosmic Rays

Anomalous cosmic rays are made of difficult to ionize elements such as the noble gases. They are created when neutral particles enter the solar system and ionize. When solar wind from the sun hits interstellar gas, the resulting shockwave accelerates these ionized particles and creates a cosmic ray.

Ultrahigh Energy Cosmic Rays

Not much is known about ultrahigh energy cosmic rays. These ultrahigh energy cosmic rays have enough energy that if you were hit with one, you would feel like you were hit on the head with a baseball.

History of Cosmic Rays

They were discovered in 1912 by Victor Hess. He took a electroscope (an instrument for detecting electric charge) and found that the higher he went in his hot air balloon, the more the electroscope went off. He thus deducted that there was radiation coming from above. He said they were part of the electromagnetic spectrum, but this was proved wrong in the 1930's when it was discovered cosmic rays were electrically charged and interacted with the Earth's magnetic field.

From the 1930's to 1950's, cosmic rays were widely popular as sources of high energy particles since linear accelerators were not available. They were crucial to discovering the existence of muons and positrons.

Cosmic Rays in Every Day Life

Cosmic rays can cause changes in soil and rock composition, can cause climate changes which lead to lightning strikes and cloud formations. Computer chip circuitry these days is so small that a cosmic ray passing through it could destroy it, and people who fly in airlines frequently can develop cancer from the heightened amount of cosmic rays up there.