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Friday, April 3, 2015

A Total Lunar Eclipse for Passover and Easter


The Olive Trees (1889) by Vincent van Gogh. Image Source: Wiki.

There will be a total lunar eclipse in the early hours of 4 April 2015, Pacific time. See the video below, or go here for viewing details.


Astronomers term four total lunar eclipses in a row a 'tetrad,' and this red moon Passover eclipse is the third in a rare tetrad. The Royal Astronomical Society of Canada confirms that there will be only eight lunar eclipse tetrads in this twenty-first century (here are their dates); this eclipse is part of the second lunar tetrad of the new Millennium. Eclipsewise describes the complicated and delicate cosmic movements behind lunar tetrads:
The lunar eclipses of 2015 are the last of four consecutive total lunar eclipses - a series known as a tetrad. During the 5000-year period from -1999 to +3000, there are 4378 penumbral eclipses (36.3%), 4207 partial lunar eclipses (34.9%) and 3479 total lunar eclipses (28.8%). Approximately 16.3% (568) of all total eclipses belong to one of the 142 tetrads occurring over this period (Espenak and Meeus, 2009a). The mechanism causing tetrads involves the eccentricity of Earth's orbit in conjunction with the timing of eclipse seasons (Meeus, 2004). During the present millennium, the first eclipse of every tetrad occurs sometime from February to July. In later millennia, the first eclipse date gradually falls later in the year because of precession.

Italian astronomer Giovanni Schiaparelli first pointed out that the frequency of tetrads is variable over time. He noticed that tetrads were relatively plentiful during one 300-year interval, while none occurred during the next 300 years. For example, there are no tetrads from 1582 to 1908, but 17 tetrads occur during the following 2 1/2 centuries from 1909 to 2156. The ~565-year period of the tetrad “seasons” is tied to the slowly decreasing eccentricity of Earth's orbit. Consequently, the tetrad period is gradually decreasing (Meeus, 2004). In the distant future when Earth's eccentricity is 0, tetrads will no longer be possible.

The umbral magnitudes of the total eclipses making up a tetrad are all relatively small. For the 300-year period 1901 to 2200, the largest umbral magnitude of a tetrad eclipse is 1.4251 on 1949 Apr 13. For comparison, some other total eclipses during this period are much deeper. Two examples are the total eclipses of 2000 Jul 16 and 2029 Jun 26 with umbral magnitudes of 1.7684 and 1.8436, respectively.
Sky and Telescope explains the stages of the eclipse:
As was the case last October 8th, this lunar eclipse favors westerners in the U.S. and Canada. And once again many will need to look low in the west as dawn brightens — lower, in fact, than last time. ... A total lunar eclipse has five stages, with different things to watch for at each. You only need your eyes to see this celestial drama unfold, though the view is certainly better through binoculars or a small backyard telescope.

The first stage begins when the Moon's leading edge enters the pale outer fringe of Earth's shadow: the penumbra. But the shading is so weak that you won't see anything of the penumbra until the Moon is about halfway across it. Watch for a slight darkening to become apparent on the Moon's celestial southeastern side (likely on the left or lower left as seen in the sky, depending on where you are). The penumbral shading becomes stronger as the Moon moves deeper in.

The second stage is the partial eclipse. This begins much more dramatically when the Moon's leading edge enters the umbra, Earth's inner shadow, where no direct sunlight reaches. With a telescope you can watch the edge of the umbra slowly engulf one lunar feature after another. Also note how the entire sky begins to grow darker, as what had been a full Moon gradually disappears. On April 4th, it'll take a good hour and a half before only a final bright sliver remains outside the umbra. By this time, the rest will already be showing a foreboding reddish glow.

The third stage is total eclipse, beginning when the last rim of Moon slips into the umbra — depending on how the edge of the umbra is defined! The edge is not sharp, since Earth has a semitransparent atmosphere. In a grazing instance like this, so critical is the adopted definition that the U.S. Naval Observatory's Astronomical Almanac (which S&T uses) lists totality as lasting 12.3 minutes, whereas Fred Espenak's Fifty-Year Canon of Lunar Eclipses says 8.6 minutes. The French national almanac lists it as 4.7.

Most of the Moon is sure to glow some shade of intense orange or red. That red light shining onto the Moon is sunlight that has skimmed and bent through Earth's atmosphere: that is, from all the sunrises and sunsets that ring the world at any given moment.
"While the Moon will be too low in a bright sky from the eastern two-thirds of the U.S., skywatchers along the West Coast and points west have a chance to see a rare close alignment of the fully eclipsed Moon and the 9th-magnitude galaxy NGC 4697. The Moon will be in total eclipse at the local times shown. North is up and stars are numbered with magnitudes." Image/Inset Sources: Stellarium / STScl via Sky and Telescope.

Sky and Telescope is also excited about this eclipse because the shadowed full moon will allow you to see some interesting sights around it. For example, right next to the moon will be one of the brightest galaxies in the lunar orbital path, NGC 4697, in the constellation of Virgo and the Virgo Supercluster of galaxies; NGC 4697's distance from us averages around 38 to 50 million light years away. The darkened moon will also allow an impressive view of our Milky Way galaxy.

"Around the time of [lunar eclipse] totality the sky will darken, allowing skywatchers a grand view of the Milky Way in the southeast. Intrepid observers may want to see if the recent nova in Sagittarius is still visible with the naked eye. Click image for charts and more information about the nova. The map shows the sky facing south from San Francisco around 5 a.m. local time." Image Source: Stellarium via Sky and Telescope.
"The full eclipse will be visible over most of the Pacific Ocean and adjacent mainland. Eastern North America will see part of the eclipse just before dawn. Much of eastern Asia and all of Australia will see the eclipse just after sunset." Image Source: NASA via Space.com.

Meanwhile, for those interested in symbolic human interpretations of these events, astrologers have plenty to say about this eclipse, combined with the total solar eclipse of 20 March 2015 and the receding Pluto-Uranus squares, all "doozies," which - they insist - reflect conflicts between rigid authority and extreme change. Astrologer Susan Miller's advice on eclipses' upheaval and change is here. Miller argues that whatever is eclipsed out of your life will be a blessing in disguise. Astrologer Kelly Rosano says: "This Full Moon eclipse is action packed" but that you should beware of "crazy town" tendencies this weekend; wait for things to settle down after Easter before making rash decisions. After that, you can plant new seeds for the future. No more procrastination! Drop your attachment to your childhood ego. Soul Garden borrows Easter rebirth symbolism; get rid of old baggage, bad habits and start a new life, with a new set of beliefs and values:
[In a] lunar eclipse ... the earth casts a shadow ... onto the moon. Now, the moon is our emotional matrix. So the earth's shadow onto the moon ... creates an emotional deficit, and in that deficit, I think things go down the toilet. I think it's a weird, interesting cosmic event. ... In all these dynamics ... reframe your story and reframe it today. ... Aries energy is basically the hero ... the part of us that lives by certain archetypes ... and usually these archetypes when it comes to the ego ... [are like] David and Goliath, [they are] ... about survival ... [you can] reframe [your attachment to the story of] ... the little guy winning ... reframe your archetype today ... as you reframe, I recommend you go higher. ... There is no battle: you have won! ... This is the hero after the struggle. ... Rise again in this new frame.
This portal "of rapid growth and healing" and "energetic vortex ... forcing us into a new territory," will take a year to 18 months to play out. The wildest (as in, Rosano's 'crazy town') interpretations mash up NASA's astronomical information with biblical scriptures and international news, such that commenters see the tetrad's third and fourth blood moons punctuating prophecies on Islamic State and Jerusalem:
The 1st and 2nd Blood Moons brought forth EBOLA, ISIS, and ISRAEL had a 50 day War with Hamas & Hezbollah.........There are 2 more Blood Moons coming and the 4th and FINAL blood moon is a SUPER Blood Moon seen in JERUSALEM!!.."On that day I will set out to destroy all the nations that come against Jerusalem." - Zechariah 12:9.
This just goes to show you that a little celestial information goes a long way in today's irrational quasi-rationality.

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