LEWISTON – Clouds and fog shrouded the sky for an hour, blocking the first-in-a-century celestial event. Then, a white disk appeared in the east.

“It’s sort of just visible,” said Gene Clough, a Bates College lecturer who peered through an oilcan-shaped telescope. “It’s not that you can’t see the spot. It’s that you can’t see the sun.”

A moment later, the sun and the spot – the planet Venus – appeared. A husband and wife, each bundled in sweatshirts, high-fived.

Looking again, Clough announced, “There it is.”

The early-morning event was called the Transit of Venus. It marks the occasion when Venus passes between the Earth and the sun. It hasn’t happened since Chester A. Arthur was president.

Today, the event is of little practical use. A few astronomers planned to use the transit to test equipment designed to find planets in faraway solar systems.

However, scientists from past days found it invaluable. Eighteenth-century astronomers used the event to figure the distances between planets. In 1769, Capt. James Cook conducted some of those measurements while in Tahiti.

When he was done, astronomers understood the vast expanse of the solar system for the first time.

The same sense of wonder drew people on Tuesday, gathering at dawn to witness something that had been unseen for 122 years.

It was cold and gloomy when they arrived, huddled around the school’s telescope. For an hour, they waited.

Jon Woodhead of Auburn woke his daughter, 17-year-old Harmony, before 5 a.m. Sleepily, they stood along with 20 others.

“Even if it doesn’t come out, I get to have breakfast with my daughter,” Woodhead said. At best, he’d see the transit, too.

“It’s just one of those rarities,” he said.

The novelty drew Susan and Rob Spellman, who brought their children, Sara, 13, and Jacob, 9. The couple home-schools their children and saw a chance for a real-life lesson.

When the fog finally cleared, the family joined the line to peer into the telescope, to see the dot that appeared on the left side.

“It looked like someone poked a hole in the sun,” Sara said.

dhartill@sunjournal.com