From the July 30, 1932, issue


When, on the afternoon of Wednesday, August 31, the shadow of the moon sweeps across eastern Canada and New England at the rate of some 2,000 miles an hour, hiding the sun for a little over a minute and a half, probably millions of people will see this most magnificent of natural spectacles, a total eclipse of the sun. In an earlier day, the event would have struck terror into the hearts of those who observed it. But now, thanks to the wide dissemination of scientific knowledge, laymen know its cause just as well as they know why the sun rises in the east in the morning and sets in the west in the evening. They can appreciate the grandeur of the eclipse without fear of its consequences.

Beautiful and impressive as the total eclipse is to the layman, it has far more importance to the astronomer. Observable eclipses are rare occurrences, and seeing one in a conveniently accessible part of the world, at a favorable time of day, and with good chances for clear weather is the chance of a lifetime. Only at the time of a total eclipse can the sun’s outer layer–the corona–be observed. So rare are total eclipses, and so short are they at best, that in the last half century, since the introduction of photography began the modern study of the sun, the corona has been observed for less than an hour.

The pearly corona of the sun, visible only during the total eclipse, is expected to appear as pictured on the front cover during the coming eclipse. This photograph was taken by the Yerkes Observatory expedition during the 1900 eclipse. Then as now, there were few spots on the sun and the streamers at the poles of the sun were short and bushy instead of long, as they are at times of sunspot maximum.

More Stories from Science News on Humans

From the Nature Index

Paid Content