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Upcoming blood moon a mix of rare celestial events: museum

2018/01/19 20:09:28

Photo courtesy of Taipei Astronomical Museum

Taipei, Jan. 19 (CNA) A total lunar eclipse that will take place on Jan. 31 offers a combination of astronomical highlights never seen before in Taiwan in modern recorded history, the Taipei Astronomical Museum said Friday.

Calling the eclipse a "five star" astronomical phenomenon, the museum said it will start at 6:50 p.m. and end at 0:10 a.m. the next day, with its full sequence visible with the naked eye across Taiwan.

It will be first time "people in Taiwan can experience a blood moon, a supermoon, a blue moon and a black moon in one package" since such astronomical events were recorded in 1800, museum researcher Chang Kuei-lan (張桂蘭) told CNA.

The only other one of its kind that will occur before 2050 will come on Jan. 31, 2037, Chang said.

During the eclipse, the full moon will have a copper hue when it becomes completely obscured by the Earth's shadow between 8:51 p.m. and 10:08 p.m., the museum said.

In a total lunar eclipse, the Earth is positioned between the sun and the moon, blocking sunlight from what would otherwise be a radiant full moon. Stargazers will see a bright full moon turn a reddish hue, hence the nickname "blood moon," according to the museum.

However, the moon does not completely disappear in a total lunar eclipse because of the refraction of sunlight by the Earth's atmosphere into the shadow cone.

This eclipse is particularly special because it involves the second and last super moon of 2018, which refers to a full moon that takes place around the time of perigee, when the moon is at its closest point to the Earth.

Since there was already a full moon on Jan. 2, the upcoming blood moon will become a "blue moon" as well, referring to the second full moon in a month.

The last time a total lunar eclipse coincided with a blue moon happened on Dec. 30, 1982, and it will not take place again until Jan. 31, 2037, according to the museum.

Furthermore, since the second full moon in January falls on the 31st, and a complete lunar cycle usually takes some 29 days, there will be no full moon in February, making it a "black moon."

A black moon can only take place in February and occurs every 19 years or so, but its classification, like a blue moon, varies from region to region due to time differences, Chang said.

A blue moon on Jan. 31 in the United States, for example, will not be described as one in Taiwan because it would be Feb. 1 in Taiwan by then, she said.

(By Lee Hsin-Yin)