MADRAS/CHARLESTON, UNITED STATES: The Sun started to vanish behind the Moon as the partial phase of the so-called Great American Eclipse began Monday, with millions of eager sky-gazers soon to witness "totality" across the nation for the first time in nearly a century.
Eclipse chasers and amateur star watchers alike converged in cities along the so-called path of totality -- when the Moon blocks out all light from the Sun -- for the main event.
Festivals, rooftop parties, weddings, camping and kayak trips and astronomy meet-ups popped up nationwide for what NASA expects will be the most heavily photographed and documented eclipse in modern times, thanks to the era of social media.
At about 1605 GMT, eclipse fans in Lincoln Beach, Oregon were the first to be able to witness the phenomenon. More than 100,000 people have gathered in Madras, Oregon, typically a town of 7,000.
Totality will begin at 1716 GMT over Oregon and end roughly 90 minutes later at 1848 GMT over Charleston, South Carolina.
The total eclipse will carve a 70-mile (113-kilometer) wide path of darkness over 14 states.
In downtown Charleston, one cafe served breakfast sandwiches and cocktails to a full house as crowds of tourists -- some in star-printed trousers -- made their way to the bustling East Coast city´s storied waterfront to stake out a prime spot.
One bar had installed outdoor speakers which blasted Bonnie Tyler´s mega-hit "Total Eclipse of the Heart" -- which she will sing on a cruise ship on Monday.
Vendor Jan Dahouas sold T-shirts emblazoned with "Eclipse 2017" and buttons that read "Keep Calm and Stare at the Sun" ahead of the main event.
President Donald Trump was expected to watch the eclipse from the White House with his wife Melania, his office said.
Many people who have seen eclipses in the past describe the experience as an emotional one, as the sky goes black, birds return to their nests and the air chills.
Experts warn that looking directly at an eclipse can cause permanent eye damage.
"The damage can really be permanent and right smack in the center of their vision," said Vincent Jerome Giovinazzo, director of ophthalmology at Staten Island University Hospital, Northwell Health.
The only safe time to look at it is for those within the path of totality -- and only during the brief moments when the Sun is completely blocked.
Everyone else should use proper solar eyeglasses, which are far darker than regular ones, or make a pinhole projector to see the eclipse while avoiding the glare of the Sun.
Cloudy weather and thunderstorms threatened to dash viewers´ hopes in some places, including Charleston. Some of the clearest views were expected along the West Coast and in the Midwest.
For those unable to witness it in person, NASA was counting down the minutes until it begins a live broadcast of the event at 11:45 am (1545 GMT).
Scientists plan to study the eclipse to learn more about the super-hot corona, or outer edge of the Sun.
Astronauts orbiting the Earth aboard the International Space Station are also planning to document the eclipse, and will get to see it three times.