Supermoon puts on a show around the world
The unusually big and bright moon happens when the Earth s satellite rock is full at the same time as, or very near, perigee -- its closest point to our planet on its monthly ellipsis-shaped orbit.
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At a distance of 356,509 kilometers (221,524 miles), this is
the closest it has been to Earth since 1948, creating what NASA described as
"an extra-supermoon."
Since the moon’s orbit is elliptical, one side (perigee) is
about 30,000 miles (50,000 km) closer to Earth than the other (apogee). The
word syzygy, in addition to being useful in word games, is the scientific name
for when the Earth, sun, and moon line up as the moon orbits Earth. When
perigee-syzygy of the Earth-moon-sun system occurs and the moon is on the opposite
side of the Earth from the sun, we get a perigee moon or more commonly, a
supermoon!
This coincidence happens three times in 2016. On October 16
and December 14, the moon becomes full on the same day as perigee. On November
14, it becomes full within about two hours of perigee—arguably making it an
extra-super moon.
The full moon of November 14 is not only the closest full
moon of 2016 but also the closest full moon to date in the 21st century. The
full moon won’t come this close to Earth again until November 25, 2034.
The supermoon of December 14 is remarkable for a different
reason: it’s going to wipe out the view of the Geminid meteor shower. Bright
moonlight will reduce the visibility of faint meteors five to ten fold,
transforming the usually fantastic Geminids into an astronomical footnote. Sky
watchers will be lucky to see a dozen Geminids per hour when the shower peaks.
Oh well, at least the moon will be remarkable.
How remarkable?
"It´s really nice," Aidan Millar-Powell told AFP
of the festive, community atmosphere at the beach. "People don´t usually
come together like this in Sydney for a natural phenomenon."
Tourists, office workers and couples crowded the Hong Kong
waterfront as the supersized moon rose over the skyscrapers of the financial
hub, while further north in the Chinese capital Beijing the moon climbed
spectacularly over the city´s skyline.
"I´ve never seen a moon this big," said Lee
Pak-kan, 44, who was watching at the Hong Kong waterfront. "The moon is
quite orange too... it´s quite special."
In the Taiwanese capital Taipei, more than 100 people queued
up to get a look at the spectacle through telescopes outside a major public
hall, while others flocked to the city´s landmark Taipei 101 skyscraper -- one
of the world´s tallest buildings -- to witness the supermoon.
"It´s quite moving, to see it up close. It´s so big, so
round, so bright," said Julia Lee, who was peering through a telescope
outside the hall.
´More super than others´
The supermoon was visible across much of India although
residents of New Delhi, the world´s most polluted capital, struggled to see it
clearly through the toxic smog that has been shrouding the city in recent
weeks.
Meanwhile, professional astronomers were at the ready at
observatories across the region to explain the phenomenon to curious members of
the public.
In Thailand, astrologers were variously predicting the
supermoon would bring disaster or great fortune.
Soraja Nuan-yoo, renowned for predicting the 2004 tsunami
that killed many in Thailand and other countries round the Indian Ocean, warned
that when the moon gets close to the Earth, "natural disasters
happen".
The supermoon also means a stronger high tide, something
that gets surfers giddy with excitement, not only at the prospect of riding
bigger waves, but doing so at night.
Forecasters had predicted higher than usual tides on
Indonesia´s Bali, a favourite with surfers.
But the holiday island was overcast and rainy when the moon
rose, with surfers deciding not to take to the waters.
A supermoon, or perigee full moon can be as much as 14%
bigger and 30% brighter than an apogee full moon. However it's not always easy
to tell the difference. A 30% difference in brightness can easily be masked by
clouds or the competing glare of urban lights. Also, there are no rulers
floating in the sky to measure lunar diameters. Hanging high overhead with no
reference points to provide a sense of scale, one full moon looks much like any
other.
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