Shot at Artistic History

Team pinpoints when Ansel Adams took 'Autumn Moon' and marks it at Yosemite.

by Diana Marcum
Fresno Bee - September 16, 2005

The sun and the moon and the mountain shadows aligned for Don Olson atop Glacier Point on Thursday night.

He knew they would. He used science.

Texas State University astrophysicist Don Olson smiles at first sight of the moonrise, in the spot he predicted, at Glacier Point in Yosemite National Park on Thursday evening. Darrell Wong / The Fresno Bee

Olson, a Texas State University astrophysicist, and his team studied the Ansel Adams' photograph "Autumn Moon" — a tableau of a rounded moon rising over sunset-splashed saw-tooth peaks — to determine exactly when Adams had snapped the shutter.

They noted that it was a waxing gibbous moon rising (an almost-full moon to the unscientifically inclined).

They studied the moon's tilt (noting a "large libation in latitude").

They used powerful software and telescopes and topographic maps to determine that Adams shot "Autumn Moon" on Sept. 15, 1948, at 7:03 p.m. Then they determined that there would be a celestial encore on Thursday night — the very same moon shadows, the same moon at the same spot in the sky as Adams' photograph. That is something that will happen only once every 19 years, or in their world, every 19-year Metonic lunar cycle.

Olson and his collaborator, Russel Doescher, have used time as their jigsaw puzzle before, sifting through heavenly forensic evidence to pinpoint such events as when and where Vincent van Gogh painted his starry skies, and when Adams shot an iconic photograph of the moon rising over Half Dome, and when the heavens would align the same way again.

An article on Ansel Adams' "Autumn Moon" photograph in Sky and Telescope magazine's October issue discusses the scientific research used to date Adams' photograph, at right.

But Thursday was different because this time the celestial sleuths came to watch their prediction.

Before, they always did the forecasting and stayed at school working while others goggled over their predicted sky scenes.

"It's almost showtime," said Olson, perched on a granite slope, his gaze moving between an 11 x 17 print of the Adams photograph and the vast horizon where the replay moment was starting. The shadows took the same shapes as in the photograph. The moon rose.

Hundreds of people trained viewfinders toward the moon. It was a night of hiking boots and tripods and few faces, all the visages blocked by cameras. Some people brought star charts and astronomy books.

Others brought their dogs and picnics.

Some had read the complete research of the event in the October issue of Sky and Telescope.

Others such as Fabrizio Mollica, 29, just happened by.

When asked whether he knew it was a special moon occasion, Mollica, from Italy, and speaking little English, nodded enthusiastically.

"Yes, yes, honeymoon!" he said, pointing to his new bride, Irene.

At 6:52, the moon was in the same spot as in the photo.

The moon rises over Glacier Point in Yosemite National Park on Thursday evening. A Texas State University team studied the Ansel Adams photograph "Autumn Moon" and determined that Adams shot the photograph on Sept. 15, 1948, at 7:03 p.m. Darrell Wong / The Fresno Bee

At 7:03, the shadows matched.

"This is our moment," Olson said quietly to himself.

The moment — the very, exact, heavens-aligned, moment — came and went with little fanfare.

"I think everyone's clock is set a little differently. I should have been counting down for people," said Ashley Ralph, an undergraduate student who worked on the project for a year.

During the evening, she repeatedly educated people on two things: It takes two minutes for the moon to travel its own diameter, and Texas State students are Bobcats, not Longhorns.

Roger Sinnott of Sky and Telescope magazine prepares his large-format camera for the moonrise at Glacier Point in Yosemite National Park on Thursday evening. Hundreds of people turned out to enjoy the moment Ansel Adams is believed to have captured on Sept. 15, 1948. Darrell Wong / The Fresno Bee

Long after the celestial moment had passed, people stood on Glacier Point gazing at lilac skies turning nighttime blue as the earth's shadow darkened the sky.

Matthew Adams, the grandson of Ansel Adams, found it fun that scientists had pinpointed when his grandfather took his picture, something Adams hadn't bothered noting.

"Not that the enjoyment of the picture would be different if it had been taken a day before or a week later," he said.

Adams didn't go to the repeat-moon-rising because he had to work at his office in Fresno, something he regretted.

"There's nothing better than kicking back on a mountaintop watching the moon," he said wistfully before the event.

And so it was on Thursday, long after the skies had darkened and the moon was something in the distance, spilling soft light on trails, that people kicked back and gazed.

Claudia Welsh, retail manager for the Ansel Adams Gallery in Yosemite, liked the attention the event turned on the work of a man who has often been called America's most important 20th century artist, but she also liked the attention it turned on the moonrise.

"How often do you get people to chuck everything and drive up a mountain to watch the moon? How often do people pause over just the wonder of it?" she asked. "Ansel would get a chuckle out of this. Somewhere he's looking down and having a nice, flattered chuckle."