Sun eerily subdued by interloping moon

May 11, 1994|By Frank D. Roylance | Frank D. Roylance,Sun Staff Writer

SIERRA BLANCA, Texas -- The quiet rangeland four miles north of this lonely truck stop grew even quieter yesterday.

As the moon's shadow crossed into Texas from Mexico and dimmed the morning sunshine, the temperature fell from 83 degrees to 71, and the desert birds settled into the sagebrush.

"They think it's evening coming," said astronomer David W.

Dunham, 51, of Greenbelt, who had traveled from Maryland to Texas seeking the best view of yesterday's solar eclipse.

The subdued sunlight was eerie, a dimness similar to the sensation a person gets at the onset of a faint. And the sun was like a winter sun, offering little warmth to the skin.

At 10:10 a.m. MDT, the two cusps or "horns" of the crescent sun looked like jet contrails on a collision course in the viewfinder of his video camera.

As seen through a plate of No. 14 welder's glass, the sun looked like a thin green ring, broken by a narrow gap at the upper right quadrant. Briefly the gap appeared almost closed.

Across much of the nation -- at schools, on shopping center parking lots, in groups or individually -- scientist and layman alike stopped to marvel at the rare show racing across the sky.

"It's weird," said 9-year-old Jennifer Hersey in Columbia, learning, to her delight, that if she made a tight circle with her thumb and index finger and let the sun shine through, the crescent image of the partially eclipsed orb would be projected on the ground.

Jennifer and her brother, 7-year-old Garrison, were taken out of Stevens Forest Elementary at 1 p.m. by their mother, Howard County General Hospital nurse Pat Hersey, to join some 300 people viewing the eclipse behind the Howard Community College cafeteria.

"They kept the kids in school today, even for recess, because they were afraid they'd look at the sun," Ms. Hersey said, alluding to warnings of eye damage if the partially obscured sun was viewed without protection.

Ross Poch, an HCC physical science professor who organized the viewing, provided a variety of eye-saving ways to view the phenomenon, including shoe boxes equipped with filters, $3.80 squares of welders' glass, a $350 Astroscan telescope and simple note cards with pinholes to project the sun's image.

Maryland, unfortunately, was not the best place for viewing yesterday's eclipse -- not only because it lay outside the 145-mile-wide path of annularity, in which the moon covered all but a ring of sunlight, but for the clouds that occasionally blocked the view as the moon moved toward its peak coverage -- a bit more than 80 percent -- at 1:28 p.m.

At Baltimore's Inner Harbor, a crowd outside the Maryland Science Center cheered when the sun peeped out from behind the clouds shortly past noon.

Science Center staff and volunteers, with members of the Baltimore Astronomical Society, provided a safe and educational afternoon for anyone who wanted to watch through pinhole devices or protected telescopes as the show ran its course from 11:41 a.m. to 3:15 p.m.

Despite the warnings of the risk of eye damage, many succumbed to their curiosity for a quick peek.

But on the Jumpers Hole shopping center parking lot about 1:25

p.m., shoppers and workers mostly saw clouds in northern Anne Arundel County.

For Dr. Dunham, the eclipse meant work -- standing amid the sagebrush on Texas Farm Road 1111 with his telescope and video recording gear to observe the eclipse with four other members of the International Occultation Association.

Dr. Dunham, who designs spacecraft trajectories at the Johns Hopkins Applied Physics Lab for a living, is IOTA's U.S. section president. IOTA's work on this eclipse is part of a continuing project of the U.S. Naval Observatory.

IOTA's task was to record the appearance of "Baily's Beads" from positions astride the southernmost edge of the moon's shadow. The beads are beams of sunlight that flash through the valleys on the rim of the moon's disk.

Michael Muschardt of Hannover, Germany, pronounced them "very beautiful."

Their data eventually will yield a precise measure of the moon's shadow, and from that computers will calculate the sun's diameter.

When compared with similar data from previous solar eclipses, the measurements may reveal changes in the sun that could affect Earth's climate.

"We were entirely successful . . . and we certainly got the data we needed," Dr. Dunham said.

Observers astride the north side of the moon's shadow, near Truth or Consequences, N.M., also reported "perfect" conditions -- clear skies and low winds, according to Dr. Dunham's wife, Joan, who remained in Greenbelt and provided a communications clearinghouse for the scattered observers.

"We have more than enough data to determine the diameter of the sun from this eclipse," she said.

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