AEGEAN SEA, South of Rhodes, Greece — As the Ocean Monarch glided through a serene blue Mediterranean on eclipse day, David Levy was explaining that solar eclipses occur in series.
The name for such a series is "Saros," said Levy, who would get on the ship's loudspeaker and narrate the events as the total solar eclipse unfolded later on Wednesday. (His narrative was a coup for the eclipse cruise: In the astronomical world, he's famous as a co-discoverer of the Shoemaker Levy 9 comet that broke into pieces and slammed into Jupiter in 1994.)
The March 29 total solar eclipse is listed by NASA as part of the same series, Saros139, which included the eclipse of March 1970, visible from Virginia Beach, Va.
From one eclipse in a Saros to the next takes 18 years, 11 days, said Levy. When that happens "an eclipse that is very similar to the previous one" will take place. Meanwhile, Earth has rotated, and the location of the eclipse changes.
This eclipse began on the east coast of Brazil. As Earth rotated, the moon's shadow flew across the Atlantic Ocean, crossed Africa, swept over the Mediterranean, and went through Russia. While it was visible as a partial
eclipse throughout much of Europe, it was total only along a band about 113 miles at the widest.
A number of the 500 or 600 eclipse-viewers aboard ship were introduced to the excitement during the March 7, 1970, eclipse. Today's eclipse will be somewhat like it, Levy says, but "this is actually a little bit longer one," with totality lasting three minutes, 53 seconds.
Asked if he is excited, Levy replies, "Oh, very much so . . . It's never routine."
Dozens of small telescopes and telephoto lenses, protective filters in place, were set up on deck, following the sun as the moon began to encroach. Passengers watched through special eclipse glasses, as a small black notch appeared in the solar disk. Slowly the notch grew into a crescent, expanded, blocked more and more of the sun's surface.
At the ship's stern, a bearded man and his 16-year-old son, residents of California, played Greek folk music on traditional instruments, adding a delightful aura. The man's wife, mother of the youth, is an artist, and she studied drawings she had made of the eclipse path. Following the cruise, they planned to drive to Bulgaria and study music.
"The shadow has raced across the Atlantic and has now reached the African continent," a man announced about 12:13 p.m. local time.
As totality approached, the light continued to dim and the waves no longer sparkled. Viewers exclaimed when the sky became dark enough to see Venus, gleaming much higher toward the apex than we ever see the planet at normal times. By the start of totality, close to 2 p.m., the light was that of late evening.
A last fierce blaze erupted from the sun, the "diamond ring effect," and then the moon covered the entire solar disk. High above, the sun was transformed into a black disk surrounded by a blazing white ring, with a less-intense outer corona.
Two bright scarlet points glittered at the moon's ebony edge; they were solar flares called prominences. Throughout the wispy corona, streaks showed the sun's magnetic lines of force.
People were shouting in amazement while others stood gaping. The ship's fog horn sounded repeatedly.
A woman said later two little girls near her were screaming, one saying it was the first eclipse she had seen "in my whole life." The woman asked her how old she was, and she replied, "Ten."
"Cried like a baby," Lance Lucero of Lakewood, Calif., said later, describing his reaction. He and his expectant wife, Raquel, hugged during the eclipse.
"It was everything that I had ever expected it to be, and more," added Lucero. "Seeing the diamond ring, I just lost it."
Michael Bakich, senior editor at Astronomy Magazine, commented, "It had the best diamond ring I've ever seen."
David Thorup, a dentist from Sandy, observed it with his wife, Carole. Though this was their fourth eclipse, they were still thrilled by the spectacle.
"Over the years I've seen many pictures of eclipses," said Thorup. But he knows there is no comparison between a photo and the actual experience, he said. "Every one has a different characteristic."
The light at the horizon differs, the corona shape is different each time. "You're always surprised," he said.
In this case, he was impressed by the "intense darkness at the center, where the moon is, and intense brightness at the edge."
Carole Thorup agreed, "It was fabulous, emotional. It's always really an emotional experience for me when it goes into totality."
The sky was the darkest the couple has seen it during an eclipse, she added. "So that was great, made it more spectacular."
Eclipse addicts will travel thousands of miles to view one of these astonishing natural events. But in 11 years, Utahns will not need to go far: on Aug. 21, 2017, a solar eclipse will cross the United States, with totality visible in central Idaho.
E-mail: bau@desnews.com