Carl Polk, age ll, of Atlanta, Ga., for his question:

What happens in the ionosphere?

We knew it was there, high above the weathery lower level of the atmosphere, because we used it to bounce radio waves. The first on that spot data from the lofty ionosphere came from man made satellites and surprised art still coming down. No man penetrated this surprising level of the atmosphere until spacemen went info titbit around the earth.

Alouette was named for a high flying lark and launched into orbit on Sept,. 28, l962. Designed to gather and relay data from the ionosphere, it was Canada's first man made satellite. But it was not the first high flying gadget to send down on the spot data from this lofty region of the atmosphere. This work started during the IGY when the space age launched early rocket probes and unmanned satellites. New and still newer data is being added constantly.

Radio taught us a great deal about the ionosphere and astronomers figured out more about its nature from the behavior of auroras. We suspected it to be the most dynamic layer of the atmosphere and the space age data proved this to be true. It begins about so miles up and reaches to more than 300 miles. At its lower boundary the thin rarefied air is cool, but the temperature aloft gradually rises to some 2,000 degrees Fahrenheit.

The ionosphere shields our lower atmosphere from dangerous solar ultraviolet and X rays. From time to time it disrupts our radio communication and magnetic compasses and rewards us with breath taking aurora displays. Without it our long distance radio would be impossible. All this occurs because the ionosphere is exposed to the sun's energy and to the bombardment of cosmic ray particles from outer space.solar radiation and cosmic bullets rip electrons from the oxygen and other rare gases. The atomic fragments become electrically charged ions and ionized gases act like good conductors. They tend to reflect the straight paths of certain radio waves. These signals zoom out and up to the ionosphere which sends them back to be picked up at distant stations on the earth. The highly charged ionosphere acts as a sort of sounding board.

But the sun's energy varies and this changes the ionosphere. When sunspot activity increases the solar output, it becomes more ionized. It shimmers with electric currents and it absorbs the radio waves it normally reflects. It gains extra magnetism and upsets compasses by competing with the earth's magnetic poles. And some of its surplus energy glows like the rare gases in a fluorescent lamp and We see the Northern Lights.

There is more to what goes on in the lofty ionosphere. We need to know all We can about it because of its role in radio. And also, We shall need it even more when we set up those fantastic global systems of communications in the space Age future. It would be nice to prevent radio blackouts and other ionosphere high jinks. But it would be unthinkable to trade such advantages for its role in broadcasting and as a shield to protect us from certain searing rays of solar energy.  

Numerous satellites have been launched to explore the details of the ionosphere.  Since the presence of an ionosphere affects living conditions on our planet we will always be curious about the complex layer of our atmosphere.  Th Goddard Space Flight Center is primarily responsible for earth orbiting unmanned scientific satellites.