Sun No Man Ever Saw

To man's naked eye the sun seems a smooth, bright disk. But astronomers have long known that its face is mottled with hot clouds of hydrogen gas, which seem to be the source of some of the radiation that periodically disrupts radio communication, and may have an important effect on the earth's weather. The clouds give off ultraviolet rays on the so-called Lyman-alpha line of the spectrum, midway between visible light and X rays. Since these rays are absorbed by the earth's atmosphere long before they can reach the ground, no earthbound camera has ever been able to make a photographic record of the clouds or their movements.

Last month scientists of the U.S. Naval Research Laboratory fitted an Aerobee-Hi research rocket with a special camera. Fired from the White Sands missile range in New Mexico, the rocket soared through the atmosphere; 123 miles up, the camera began clicking. The camera was fitted with a mirror ruled with a grating of fine lines, 15,000 to the inch, designed to filter out the sun's glaring visible light, which otherwise would have overwhelmed the Lyman-alpha rays given off by the clouds. To keep the camera stabilized in the nose of the yawing rocket, University of Colorado physicists had devised a highly sophisticated motor-operated mount, equipped with photoelectric cells that locked on the sun and kept the camera aimed directly at it.

The result, released last week, was an image of the sun no man on earth has ever before seen. Clouds of hot (6,000DEG C.) hydrogen gas, swirling 4,000 to 6,000 miles above the sun's surface, showed up in the photographs as white blotches above the dark areas of lower-altitude gas. Aided by photographs taken in two other wave lengths of visible light from ground stations in California, New Mexico, Michigan and Washington, D.C., the Aerobee's photographs give astronomers a sort of three-dimensional picture of the violent energy processes in the sun's atmosphere. Eventually, such rocket photography may become so refined that meteorologists may be able to make daily solar weather reports as a matter of routine to help them predict earth's weather.

This file is automatically generated by a robot program, so reader's discretion is required.