David stalnaker, age 12, of Newport News, Va., for his question:
Where do cosmic rays originate?
The life story of cosmic radiation is immense in scope and very long. The speeding particles of cosmic rays are indeed children of the COSMOS, spawned there perhaps millions Of years ago. Those that strike our upper atmosphere have accidentally collided with the earth.
From the Earth, the heavens above the weathery atmosphere look calm and serene. The daytime sky of peaceful blue changes after sunset to silent black, and black is the color of the vast reaches of outer space seen above the atmosphere. As scientists began to explore the edgeb Of outer space, they soon learned that the cosmos is far from serene. Space is far from empty and far from calm.
It is occupied by speeding sub atomic paiticles and seeths with various forms of electromagnetic energy. It is Swept by cosmic winds and torn by cosmic storms. On a grand scale these cosmic upheavals are a little like the weather on our planet. They are born of cosmic particles at the mercy of cosmic energies.
This seething fabric of space is ca11ed plasma. And the particles we call cosmic rays are part of this cosmic radiation. Most of them are positive protons formed when single electrons are torn from hydrogen atoms. Many are positive ions of helium atoms, and a few are ions of larger atoms. Vast quantities of such particles are spawned in the seething nuclear furnaces of the stars and strewn into space.
These traveling particles are the primary cosmic rays that strike our upper atmosphere. On the way down they bash and shatter air molecules, and these atom smashing collisions send showers of secondary cosmic rays onto the Earth. The speed energy of the primary particles telis the experts something of their history.
Some originate in the sun, but most primary rays are born in Exploding stars and other cosmic disasters of long ago and far away. The speeding debris may be trapped and tossed in vast magnetic fields where the particles gain energy. After perhaps 10 million years they swoop free and sweep through the universe. Some of these fragments from distant disasters strike our small planet as primary cosmic rays.
We are bombarded day and night with these cosmic bullets from outer space. The attack varies at different t7.mes and places, but in an average minute Every square inch of our planet is struck by 50 to 200 primary cosmic particles. Thus Ends a space traveling story that may have originated in a nova Explosion hundreds of light years away and millions of Earth years ago.