The Sun’s Corona

Hundreds of distinguished American and European astronomers gathered in southwest California and northwest Mexico and staked weeks of time and thousands of dollars on the chance of two minutes and 58 seconds of clear weather last Monday to permit them to make the scientific observations and photographs of a total eclipse of the sun (TIME, Sept. 3, Sept. 10).

On Santa Catalina and San Clemente islands, off the coast near Los Angeles, and at San Diego, Ensenada, Mexico and other Lower California posts, the sky was obscured by heavy clouds practically throughout the eclipse. At Los Angeles the clouds parted just long enough for the watching thousands to see a thin crescent of shadow on the disk in the early phase. At Mexico City the clouds were more polite, and a good view was obtained, though as the Mexican capital was just outside the belt of totality, with an obscuration of 99.4%, none of the major expeditions had stationed themselves there. There is a possibility that later reports from points in the interior of Mexico along the path of the eclipse will show that some valuable data were obtained. At Havana, a little to the north of the totality zone, a tropical storm broke just before the eclipse, ruining the prospect. In New York, where the maximum eclispe was 46%, weather conditions were excellent, and many photographs and observations were made by home-staying scientists, and laymen with the usual paraphernalia of smoked glass, dark spectacles and pin-prick holes.

The astronomers for the most part took the blow philosophically. They have learned by years of patient experience that the wonders of the heavens are no respecters of mere human beings. Many of the expeditions went through their programs regardless, took long-exposure pictures, and attempted to measure heat changes and refraction in almost total darkness, but there is little hope that any data of value will result. At least two of the expeditions were insured against bad weather—the first time in astronomical history that such precautions have been taken.

Two important types of observation were possible. Army and Navy aviators, from their headquarters at Rockwell Field, San Diego, mounted from 16,000 to 20,000 feet, above the clouds and fog, flew out over the ocean, snapped the eclipse at 80-mile intervals previously mapped out between Santa Barbara and San Lower California. Each plane was manned by a pilot and a photographer. Lieut. John Macready, transcontinental non-stop flyer, and George Stephens, the Army’s crack photographer, ran into a heavy rainstorm and secured nothing. But aviators from the battle fleet squadrons, under command of Captain V. Marshall, secured satisfactory photographs of the eclipse, including the sun’s corona.

Further, observations of the disturbance of magnetic conditions and compass aberrations during the eclipse were made from the Carnegie, the world’s only nonmagnetic ship, commanded by Captain Ault.

There will be a total solar eclipse in New England in the Winter of 1925, but the sun will be too low on the horizon for good observation. There will be no other good chance in any populous region for many years.