None of us will likely see Venus pass, like a moving beauty spot, across the face of the sun again.
And the historical enormity of that fact wasn't lost on Nancy Nance and Cathy Johns, both of Lake Tahoe, on Tuesday evening at Western Nevada College's Jack C. Davis Observatory in Carson City.
"It's phenomenal that it happened in my lifetime," Nance said. "And May 20th, to have that, too. There are eclipses, but for us to see it here so clearly is wonderful."
Believers in astrology - a word kept on the down-low at the astronomy-minded observatory - have also been stoked about this active celestial season. Were Nancy and Cathy giving any credence to the predictions of life-changing significance for 2012?
"Someone's always saying that at some time," Johns said through a skeptical laugh.
Yet Nance didn't dismiss outright the cosmic belief system and its plethora of prognostications.
"I listen to both, but unless they can prove that to me, then... I'll listen to it and I'll go, 'uh-huh.' You know, I'm not going to say, 'Oh, you're crazy!' Interesting, that's exactly how I view it."
From the U.S. to South Korea, people around the world turned their attention to the daytime sky on Tuesday and early today in Asia to make sure they caught the rare sight of the transit of Venus. The next one won't be for another 105 years.
"If you can see the mole on Cindy Crawford's face, you can see Venus," Van Webster, a member of the Los Angeles Astronomical Society, told anyone who stopped by his telescope for a peek on Mount Hollywood.
For astronomers, the transit wasn't just a rare planetary spectacle. It was also one of those events they hoped would spark curiosity about the universe and our place in it.
Sul Ah Chim, a researcher at the Korea Astronomy and Space Science Institute in South Korea, said he hoped people see life from a larger perspective, and "not get caught up in their small, everyday problems."
"When you think about it from the context of the universe, 105 years is a very short period of time and the Earth is only a small, pale blue spot," he said.
The transit was happening during a 6-hour, 40-minute span that began just after 6 p.m. EDT in the United States. What observers could see and for how long depended on their region's exposure to the sun during that exact window of time, and the weather.
Those in most areas of North and Central America saw the start of the transit until sunset, while those in western Asia, the eastern half of Africa and most of Europe could catch the transit's end once the sun came up.
Hawaii, Alaska, eastern Australia and eastern Asia including Japan, North and South Korea and eastern China get the whole show since the entire transit happens during daylight in those regions.
While astronomers used the latest technology to document the transit, American astronaut Don Pettit aboard the International Space Station was planning to take photos of the event and post them online.
Online streams with footage from telescopes around the world proved popular for NASA and other observatories. A NASA stream midway through the transit had nearly 2 million total views and was getting roughly 90,000 viewers at any given moment.
Meanwhile, terrestrial stargazers were warned to only look at the celestial event with a properly filtered telescope or cardboard eclipse glasses. If the sun is viewed directly, permanent eye damage could result.
In Los Angeles, throngs jammed Mount Hollywood where the Griffith Observatory rolled out the red carpet for Venus. The last time the city witnessed a Venus transit was 130 years ago in 1882. A 2004 transit was not visible from the western U.S.
Telescopes with special filters were set up next to the lawn and people took turns peering at the sun before and during the transit. Astronomers and volunteers lectured about the rarity of a Venus pass to anyone who would listen.
• Nevada Appeal news editor John R. Kelly and The Associated Press contributed to this story.