A dark red shadow crept across the moon Saturday during the first total lunar eclipse in nearly three years, thrilling stargazers and astronomers around the world.

Partly visible on every continent, residents of Europe, Africa and the Middle East had the best view of the phenomenon, weather permitting.

About a dozen people gathered at the Croydon Observatory in southeast London to watch the start of the eclipse.

"It's starting to go!" said Alex Gikas, 8, a Cub Scout who was studying for his astronomy badge. "I've never seen anything like it before. I'm really excited."

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The eclipse was clearly visible, thanks to clear, crisp weather in southern England.

Lunar eclipses occur when Earth passes between the sun and the moon, an uncommon event because the moon spends most of its time either above or below the plane of Earth's orbit.

Sunlight still reaches the moon during total eclipses, but it is refracted through Earth's atmosphere, bathing the moon in an eerie reddish light.

Mike Ealay, a 60-year-old architect, said the deep red color of the moon made it look like a close-up version of Mars.

"I think it's quite exciting. It's like having the red planet on your doorstep," he said.

Despite cloudy conditions over much of Europe, a variety of Webcasts carried the event live, and astronomers urged the public not to miss out on the spectacle.

"It's not an event that has any scientific value, but it's something everybody can enjoy," said Robert Massey, of Britain's Royal Astronomical Society.

Earth's shadow began moving across the moon at 3:18 p.m. EST, with the total eclipse occurring at 5:44 p.m. and lasting over an hour.

Residents of east Asia saw the eclipse cut short by moonset, while those in the eastern parts of North and South America had the moon already partially or totally eclipsed by the time it rose over the horizon in the evening.

While eastern Australia, Alaska and New Zealand missed Saturday's show, they will have front row seats to the next total lunar eclipse, on Aug. 28.

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