Stargazers in the Americas and Asia were treated to a lunar eclipse Wednesday, a celestial show that bathed the moon in a reddish tint to create a "blood moon".

During the total lunar eclipse, light beams into Earth's shadow, filling it with a coppery glow that gives it a red hue.

The early phase of the eclipse began at 0800 GMT, or 4:00 am, on the east coast of the United States.

NASA provided live footage via telescope of the eclipse, showing a black shadow creeping across the moon in a crawl that took about an hour.

Only when the moon was totally eclipsed did the redness appear. The total eclipse was also to last about an hour, and ditto for the return to its normal colour. The total eclipse happened at 6:25 am on the US east coast (1025 GMT).

The NASA web site was peppered with Tweets bubbling with questions and comments on the heavenly phenomenon.

"This is amazing. Thank you for this opportunity," read a Tweet from the handle @The Gravity Dive.

"Is there any crime increase during this process? Any psychological problems?" wrote a person who identified herself as Alisa Young.

Just before the climax, Kathi Hennesey in California wrote, "Watching from San Francisco Bay Area. Just a sliver now."

Ring of fire

A NASA commentator explained that during the total eclipse, if you were standing on the moon and looking at the earth, you would see it all black, with ring of fire around it.

In Hong Kong, free viewing locations were set up on a harbourside promenade by the Hong Kong Space Museum for the public to observe the various phases on telescopes.

In Tokyo's Roppongi fashion and entertainment district, enthusiasts performed yoga exercises under the blood moon. Many others had climbed atop the city's skyscrapers to view the sky.

On Australia's east coast, a live video feed set up by the Sydney Observatory was hit by cloud cover, thwarting some viewers.

In New Zealand, the moon will be close to its highest point in the sky, according to Auckland's Stardome Observatory & Planetarium, making for a view of the spectacle unobstructed by buildings.

The event was not visible in Africa or Europe, NASA said.

The eclipse is the second of four total lunar eclipses, which started with a first "blood moon" on April 15, in a series astronomers call a tetrad.

The next two total lunar eclipses will be on April 4 and September 28 of next year.

The last time a tetrad took place was in 2003-2004, with the next predicted for 2032-2033. In total, the 21st century will see eight tetrads.