Millions turned their eyes to the sky on both sides of the Pacific as a solar eclipse created a "ring of fire" from Asia to the western United States, where it was greeted with whoops in California.
The annular eclipse was visible from parts of China early Monday before moving westwards across Taiwan and Japan, and was continuing across the Pacific on a 13,600-kilometre arc ending in Texas late Sunday local time.
"That was totally awesome," said Geoff Reid, 28, from Santa Cruz, at a huge "viewing party" on a terrace overlooking Los Angeles, after a New Year's Eve-style countdown climaxed with huge cheers at the eclipse's peak.
"We're on holiday with the kids, visiting Disneyland. Then we heard this was happening, we had to come," said British tourist Ian Hunter, among thousands gathered at the hill-top Griffith Observatory, near the iconic Hollywood sign.
In Asia, clouds across much of southeastern China prevented a clear view, with some early risers in Hong Kong able to see only a small sliver of the "annular" eclipse and others coming away disappointed.
An annular eclipse occurs when the moon passes in front of the sun, but is too far from the Earth to block it out completely, leaving the "ring of fire" visible.
However, many in Tokyo got a spectacular sight as the sprawling Japanese capital of 30 million people received its first glimpse of the phenomenon in 173 years.
Sadanobu Takahashi, 60, from Japan's northern Akita prefecture, said he and his wife joined a special two-day tour of Tokyo to watch the eclipse from the top of a 54-storey building in the Roppongi district.
"Look! Now it's a perfect ring. How wonderful!" he cried out.
Around 200 people were gathered on the roof terrace, where two-year-old Hikaru Ichikawa ran around with special viewing glasses designed to protect his eyes, shouting: "I can see it! I can see it!"
Commuters from businessmen to schoolchildren stopped on the streets of Tokyo to watch as the eclipse developed, cheering when it became visible.
Japan's major television stations cut live to the once-in-a-lifetime event, which has generated a mini-boom in spending on special tour packages and viewing glasses. Japan Airlines laid on a sold-out observation flight.
Electronics giant Panasonic sent an expedition to the top of Mount Fuji, Japan's highest mountain at 3776 metres, to film the phenomenon using solar-powered equipment.
In Hong Kong, a few thousand optimistic early birds gathered on the Victoria Harbour waterfront hoping to catch a glimpse of the spectacle, but heavy cloud cover gave them only a brief window of less than a minute.
"Who could not be disappointed?" said Thomas Goethals, a tourist from Belgium.
Others higher up in Hong Kong got a marginally better view through the clouds, and many of the viewers on the harbourfront resorted to taking photos of each other holding up their protective filters.
Thousands in the western United States were banking on clearer skies as they ventured out at sunset on Sunday.
One of the best spots in North America to see the full ring of fire effect was the tiny town of Kanarraville, Utah, where the local population of 350 was invaded by thousands of eclipse-watchers.
T-shirts, flags and and bumper stickers touted the town as the eclipse "sweet spot," and there were also loud whoops when the full, annular eclipse was reached, some people watching through welders' masks.
"I thought Utah was as good a gamble as any," David Lee, a member of the Royal Astronomical Society from Victoria, Canada, told the Salt Lake Tribune.
Further west in Los Angeles, thousands were gathered for the viewing party at the Griffith Observatory. Roads were gridlocked and many people hiked up through the Hollywood hills to reach the event.
In the cloudless skies over densely populated southern California, the eclipse peaked at 86 percent of the solar diameter, still blinding to the naked eye, but like a reverse crescent moon when viewed through a solar filter.
The observatory ran out of $US2.99 eclipse glasses two days before the event, and on Sunday was only selling larger "solarama" shields, limited to two per family to see the eclipse, the most spectacular in LA for 20 years.
"It's amazing, it's phenomenal. It's unlike anything I ever expected, so I'm very excited to be here," said Dena Fargo, adding that it was the first eclipse she had ever seen "and I'm nearly 40, so it's about time".