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WASHINGTON -The moon has turned red in the skies above North and South America at the start of a rare series of lunar eclipses some fear signals the end of the world.
The so-called ‘blood moon’, which occurs when the Earth’s shadow passes over the moon , will be repeated three times this year and next. The phenomenon, known as a tetrad, will not happen again until 2032. Previous tetrads have coincided with significant religious events and the current series of ‘blood moons’ aligns with a number of Jewish holidays.
Some Christians are worried the event could have catastrophic consequences, referring to a passage in the Bible that states: ‘The Sun shall be turned into darkness, and the moon into blood , before the great and the terrible day of the Lord comes.’ Astronomers in North and South America were able to see the ‘blood moon’ for about 80 minutes, with Earth’s celestial neighbour in at least a partial eclipse phase for three hours and 30 minutes.
However, skywatchers in most of Europe, Africa, the Middle East and Asia were out of luck because the event happened after moonset. The second blood moon of the year will occur on October 8, with the tetrad’s remaining two expected on April 4 and September 28, 2015.
In a total lunar eclipse , the full moon turns a coppery red as it passes into Earth's shadow. During the process, the moon 's bright glow dims, taking on a red hue because of shimmers of sunlight and sunsets seeping through the Earth's atmosphere.
Dust and sulfur dioxide in the Earth's atmosphere can affect the size of the shadow. The moon has to be full for the total lunar eclipse to occur. As more of the moon emerges from the shadow, its red tint fades as it gets lighter and transitions to its normal silver color. The entire reddening process takes about an hour.
In Tuesday's spectacle, clouds hid the view from half of the United States, but cities such as Dallas, Denver and Los Angeles had optimal, front-row seats. "Woke up in just enough time to see half of the blood moon ,"tweeted LaTara Hammers of Columbia, Missouri. "It's so cool how the universe works."
South and North American residents watched the entire spectacle, while observers in the Western Pacific caught the second half of the event. Central Asia and some parts of Europe and Africa didn't see much - the moon was setting in most of those continents during the eclipse .
"You know what's even weirder than the 'blood moon '? The entire solar system and how amazing it perpetually is always while we barely notice," Johnny Argent tweeted. Ed Krupp, director of the observatory, described it as a "typical copper red" total lunar eclipse . Though rare, it's the sky "conspiring into a special event" that helps draw crowds, he said.
"The fact that there are four lunar successions coming this year and next ... is unusual," Krupp said. "But it's not the kind of thing astronomers get worked up about. It doesn't really mean anything. It's a chance arrangement of gravity and the motions of objects in the solar system, primarily the Earth and moon ."
Unlike solar eclipses, lunar eclipses are safe to view with the naked eye and don't require special filters.
The rare sight and was virtually unheard of a few centuries ago. Before the 20th century, there was a 300-year period when there were no blood moons, said Fred Espenak, a NASA eclipse expert. "The most unique thing about the 2014-2015 tetrad is that all of them are visible for all or parts of the USA," he said.