Although a scientific phenomenon, there are lots of myths about moon changing its colour to red [GALLO/GETTY]

Skywatchers have witnessed the moon's appearance change as sunlight was blocked by the earth on the winter solstice.

In Los Angeles, California, astronomy enthusiasts gathered to learn about the rare celestial event despite its visibility being obscured by heavy cloud cover.

US skywatchers who stayed up and had clear skies saw a total lunar eclipse early on Tuesday morning, a rare event for the winter solstice.

A total lunar eclipse happens when the Earth gets in between the sun and the moon, casting what is in effect a big shadow and making it look as if the moon is disappearing before your very eyes.

The eclipse began at about 1:32am local time Tuesday December 21 on the East Coast, and 10:32pm Monday December 20 on the West Coast.

As the total eclipse approached, the moon's appearance changed from a bright white ball to a tiny white sliver before appearing red and then brown, as it was hit by a diminishing amount of sunlight.

The last time a total lunar eclipse coincided with the full moon of the winter solstice was in 1638 and it is not expected to recur until 2094.

'Amazing to see'

Francisco Diego, London-based astronomer told Al Jazeera that, "The moon should disappear completely because it doesn't get the light from the sun, but it doesn't [disappear], because the earth has an atmosphere, which is filtering the rays from the sun and changing the direction," he said. 

"And they hit the moon, but only the ray lights hits the moon then the moon acquires this kind of orange-red colour, which is amazing to see," he added.

In Los Angeles, scientists and guests at the Griffith Observatory in Hollywood continued studying the once-in-a-lifetime eclipse, despite their inability to see it during one of the rainiest weeks on record in southern California.

Ed Krupp, Griffith Observatory director said that, "Any lunar eclipse is interesting because the atmosphere changes how it looks, every eclipse has its own particular properties, that makes it interesting.

"The fact that it falls on the winter solstice is kind of unusual, it adds some colour to the whole event."

"For this whole west coast longitude, this is the highest lunar eclipse that we've had since 419 AD. If we could see this eclipse, we'd be putting our heads way up to the sky to look at it."

Educational seminars regarding the eclipse continued in the rain, and although guests could see only grey cloud cover from the powerful optical telescope, they did not let the rain dampen their enthusiasm.

"Scientifically, by looking at the way the moon looks during the eclipse, we can tell about the composition of the atmosphere at that very moment," Diego said.

Source: Al Jazeera and agencies