The spectacle of tiny Venus passing across the face of the sun awed observers around the world Tuesday, as people from Australia to the United States squinted skyward or hunched over telescopes for the rare event.

Many came with a sense of cosmic wonder, some were only puzzled.

"How come the sun had a black dot in it?" Dorcas Tam, 7, asked in Hong Kong.

Across the Midde East — well-positioned to see the entire six-hour transit — viewers took to the mountains in Lebanon, the desert in Jordan and the pyramids in Egypt to get a glimpse.

People in Africa and Europe could also see almost the entire show, while the northeast corner of the United States and Canada would see only the tail end of the event.

"The hook that got people was that there was no one in our lifetime who had ever seen it. My son Daniel got gripped by that," said Debbie Musselwhite, who came with 10-year-old son to join several hundred people at the Royal Observatory (search) in Greenwich, England.

"It's a brilliant opportunity to know the mechanics of our solar system," said another visitor, Shereeza Feilden, 14.

Some people were waiting in line at 6 a.m. for a chance to use one of the filter-equipped telescopes provided by the observatory, said Emily Winterburn, curator of astronomy.

The Royal Observatory, beside the Thames in southeast London, has a historic connection to the transit, which occurs twice — eight years apart — about every century. In 1716, Edmond Halley of comet fame observed the transit at Greenwich to calculate the distance between the Earth and the sun.

Planetariums the world over — from India's eastern city of Bhubaneswar to Boston — set up telescopes with eye-protecting solar filters.

In the United Arab Emirates, the Astronomical Society set up an air-conditioned tent, providing telescopes and lectures — along with chocolates and water for those coming in from the 111-degree heat. "With this big event, we had to let the public share our passion," said the society's chairman, Khalfan Sultan al-Noaimi.

"One day, I want to be a pilot and reach up there," said Nemr Ramzi, a 10-year-old Palestinian, who was in the tent.

In Bahrain, state-run television aired documentaries on Venus. A group of science students at an observation point discussed whether they should collectively perform a special prayer often said during solar eclipses.

"Any phenomenon is related to religion, and we are Muslims. The simplest thing to do is to pray to God. ... We are thanking him on every occasion," said Mohammed Youssef, an assistant professor of physics.

In Greece, two American experts stationed themselves at opposite ends of the country — the southern island of Crete and the northern city of Thessaloniki — in hopes of unlocking the mystery behind the "black drop effect," which makes Venus appear teardrop shaped instead of a circle when it aligns with the edges of the sun.

"It's like a fine French wine for the people who know about it and enjoy it," gushed Jay Pasachoff, an astronomer at Williams College in Massachusetts, as he watched the event from the observatory of the Aristotle University of Thessaloniki (search).

Pasachoff's team collected data on Venus' atmosphere. It also took advantage of the transit to refine techniques for studying so-called exoplanets orbiting distant stars. The used 12 telescopes and NASA's Transition Region and Coronal Explorer spacecraft, known by its initials as TRACE (search), to observe the transit.

About 500 people were lined up at 5 a.m. in Boston to take a turn at a telescope atop the Harvard Smithsonian Center for Astrophysics.

A blue sky over Sydney gave about 40 people looking through telescopes at the city's observatory a clear view.

The sight had special significance for Australians — this country's east coast was "discovered" by British explorer James Cook on his way home from viewing the 1769 transit in Tahiti.

Rain and cloud obscured the show in Japan and Thailand. It also was cloudy in Hong Kong, but that didn't stop more than 100 people queuing up at the Hong Kong Space Museum (search), where several telescopes were waiting.

Cristy and Robert Sears, amateur astronomers from Bellingham, Wash., came to Paris for the event.

"The beginning was exciting. There was a lot of oohing and ahhing," Cristy Sears said, then added with a laugh: "But we forgot to bring the champagne."

In a park in Oslo, Norwegian astronomer Knut Joergen Roed Oedegaard proposed to his girlfriend Anne Mette Sannes on a stage in front of about 2,000 people gathered to watch the transit. She said yes to thundering applause.

A key viewing location in Britain was Carr House in Much Hoole in northwest England. A telescope was set up in the bedroom where astronomer Jeremiah Horrocks observed the transit for the first time on Nov. 24, 1639.

"It was a bit surreal to be stood here and think this is the spot where Jeremiah Horrocks was when he saw the transit all those years ago," said Riddhi Gupta, 16, one of three New Zealand students who won a competition to come to the event.