Many people of a certain age may
remember a particular sketch performed by two iconic animated cartoon
characters, Bugs Bunny and Daffy Duck. The two have a heated, comical debate about
whether it's duck season or rabbit season.
But
if such a deliberation were to occur now, an astronomer could easily put an end
to it by declaring that neither Bugs nor Daffy is correct.
For,
in truth ... right now, it's eclipse season! [Solar Eclipse Guide: When, Where & How to See
Them]
More
on this in a moment, but first let me tell you that during this first month of
the new year we will have two eclipses, one of the sun and one of the moon. The
lunar eclipse will be total, well-publicized and visible (weather permitting)
to literally billions of skywatchers.
The
sun eclipse, due to occur this upcoming weekend, is another story.
Total
solar eclipses can be seen
only when the dark shadow cone of the moon, called the umbra, touches Earth's
surface. For this upcoming eclipse, that cone will completely miss the Earth,
passing approximately 560 miles (900 kilometers) above the North Pole. But the
moon's outer shadow, or penumbra, will scrape a part of the Northern
Hemisphere, resulting in a partial eclipse that will be visible to varying
extents from Eastern Asia — most notably over Siberia, much of Mongolia,
northeast China, Japan and Korea. Around the time of local sunset, the penumbra
will also sweep a large swath of the North Pacific Ocean, as well as southwest
Alaska, including the Aleutian Island chain.
The moon will block part of the sun
during a partial solar eclipse on Jan. 5-6, 2019 during the first new moon of
2019. The partial solar eclipse will be primarily visible from East Asia and
parts of Alaska.
As
this shadow progresses east over the Earth's surface, it will pass across the international
date line, resulting in a change in calendar date for the eclipse. To the west
of the date line, over eastern Asia, the eclipse will happen on the morning of
Sunday, Jan. 6. But to the east of the date line, over Alaska, the eclipse will
happen during the afternoon of Saturday, Jan. 5.
So,
on a worldwide basis, this eclipse will end the day before it begins!
Best
views from East Asia
How Solar Eclipses Work: When the
moon covers up the sun, skywatchers delight in the opportunity to see a rare
spectacle. See how solar eclipses occur in this Space.cominfographic.
Credit: Karl Tate, SPACE.com
Contributor
The
greatest eclipse will take place over Siberia, in the Srednekolymsk District in
the Sakha Republic of Russia (population 3,525), a region whose economy largely
relies on fishing, farming of reindeer and hunting for pelts. Here, the very low winter sun only
barely clears the southern horizon and is visible for just 2 hours a day. But
on Sunday, five-sevenths of the sun's diameter will be hidden behind the moon
at midday. The normally thick haze near the horizon could somewhat attenuate
and redden the sun's light, making the sun look like a slice of cantaloupe.
From
other locations, the moon will appear to take a much smaller bite out of the
sun. Over East Asia this will be a mid- to late Sunday morning event. Tokyo
will see 30 percent coverage; Seoul, South Korea, will get 24 percent, and
Beijing 20 will see percent. Meanwhile, Taipei, Taiwan, will see barely any
eclipse: Less than 2 percent of the disk area of the sun will be obscured as
seen from there.
A
list of local circumstances for these and other cities in China, Japan, South
Korea and Taiwan has been compiled here,
courtesy of astronomer Fred Espenak of eclipsewise.com.
It's now "prime time" for eclipses!
So,
what is an eclipse season? It is a span of about a month during which eclipses
are possible at both new and full moons, because the line of the nodes of the
moon's orbit are pointed near enough to the sun. The moon's orbit is tilted to
the orbit of the Earth at an angle of just over 5 degrees; the nodes are the
two points at which the planes of the two orbits intersect — that is, the two
points at which the moon appears to cross going either up or down through that
imaginary line in the sky called the ecliptic.
More
often than not, at new moon,
the moon will pass either above or below the sun, so no solar eclipse takes
place. Similarly, at full moon,
the moon will glide either above or below the shadow cast by Earth, so no lunar
eclipse occurs. But when the times of new and full moon occur at or close to a
nodal crossing point, an eclipse is possible.
On
Monday, Jan. 7, at 0008 GMT (7:08 p.m. EST), the moon will arrive at the
descending node of its orbit — it will cross the ecliptic heading south. But
new moon will occur 22 hours and 39 minutes before the nodal crossing. That's
close enough to the node to produce an eclipse of the sun but far enough from
the node that only a part of the sun will be covered.
Later this month
After the
eclipse, the moon will continue on its way in its orbit around the Earth. On
Sunday, Jan. 20, at 2244 GMT (5:44 p.m. EST), the moon will arrive at its other
(ascending) node and cross the ecliptic while heading north. Just 6 and
one-half hours later, the moon will turn full. And that full moon will be not
only close enough to the node to enter the Earth's shadow, but also close
enough to pass completely into the shadow and produce a dramatic total eclipse.
This
event will strongly favor the Western Hemisphere: North and South America will
be facing directly toward the moon when totality occurs. Europe, too, will get
a look just prior to moonset, early on Monday morning, Jan. 21.
Space.com
will provide all the details of this spectacular sky show in the coming days,
so stay tuned!
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