Jamie Jetton took the day off from work to bring her two nephews, 6 and 11, visiting from Arizona, to the observatory. Sporting eclipse glasses, it took a little while before they spotted Venus.
"I'm still having fun. It's an experience. It's something we'll talk about for the rest of our lives," she said.
Bo Tan, a 32-year-old software engineer took a half day off from work and went with his co-workers to the observatory. He admitted he wasn't an astronomy buff but could not miss this opportunity.
He pointed his eclipse glasses at the sun and steadied his Nikon camera behind it to snap pictures.
"It makes you feel like a small speck in the universe," he said.
Clouds obscured the view in Tokyo, but students and other viewers under clearer skies in southern and western Japan were seen on TV using dark lenses to gaze at the sun. One child remarked that it looked as if the "sun had a mole on its face."
In India, where astrology is so popular it influences decisions from when to get married to who should run for office, hundreds of enthusiasts gathered at New Delhi's planetarium to see Venus cut a path across the Sun.
"Celestial events, especially rare ones like this, generate a lot of public interest," said Rathnasree Nandivada, director of the planetarium. During the last Venus transit in 2004, more than 10,000 people visited the planetarium.
There was no disappointment for those who watched the planetarium's webcast of the celestial event from India's Astronomical Observatory in the Himalayan region of Ladakh — the world's highest observatory, at 14,800 feet (4,511 meters).
The low oxygen and air pressure along with minimal cloud cover over the station provide optimal conditions for sky viewing, according to Raghu Kalra, one of several volunteers for the Amateur Astronomers Association who provided the webcast feed from Ladakh.
In Mexico, at least 100 people lined up two hours early to view the event through telescopes or one of the 150 special viewing glasses on hand, officials said. Observation points were also set up at a dozen locations.
Venus, which is extremely hot, is one of Earth's two neighbors and is so close in size to our planet that scientists at times call them near-twins. During the transit, it will appear as a small dot.
It was the seventh transit visible since German astronomer Johannes Kepler first predicted the phenomenon in the 17th century. Because of the shape and speed of Venus' orbit around the sun and its relationship to Earth's annual trip, transits occur in pairs separated by more than a century.
It's nowhere near as dramatic and awe-inspiring as a total solar eclipse, which sweeps a shadow across the Earth, but there will be six more of those this decade.
In Hawaii, hundreds of tourists and locals passed through an area of Waikiki Beach where the University of Hawaii set up eight telescopes and two large screens showing webcasts of the transit as seen from telescopes at volcanoes on other Hawaiian islands.
But minutes after Venus crossed into the sun's path, clouds rolled overhead and blocked the direct view.
"It's always the challenge of being in Hawaii — are you going to be able to see through the clouds," said Greg Mansker, 49, of Pearl City, as he stood in line at a telescope.
The intermittent clouds didn't stop people from looking up through filters, but it did drive some to crowd the screens instead.
Jenny Kim, 39, of Honolulu, said she told her 11-year-old son the planet's crossing would be the only time he'd get to see the transit in person.
"I don't know what the future will be, so I think this will be good for him," Kim said as she snapped photos of the webcast with her smartphone.
Astronomers also hosted viewings at Pearl Harbor and Ko Olina. In Maui, 20 couples renewed their vows during a ceremony tied to the transit at the Hyatt Regency Maui, a spokeswoman said.
Some observers at the University of Alaska, Anchorage gathered on a campus rooftop, peering at Venus through special filtered glasses and telescopes.