Anonymous asked in Science & MathematicsAstronomy & Space · 6 years ago

Probability of 2014/15 four lunar eclipses (Tetrad), all on a Jewish holiday?


A Lunar Tetrad happens when four consecutive total lunar eclipses are repeated after each other. In 5000 years we have 3479 total lunar eclipses. That gives us 1.437 each year. During the same time we have 142 Lunar Tetrads. Since 33 a.C we have had seven Tetrads with all the eclipses at Jewish holidays. A solar year has 365.25 days while a lunar year has 354.37 which the Jews use for their fix date of passover.

In 2014/15 we will have the eight Tetrad with all four eclipses falling on one of the seven Jewish holidays.

What is the statistically probability of:

– Total lunar eclipse tetrad (Four total lunar eclipses in a row? We have 5000/142=35.21 years in-between each one.

– That we have a Total solar eclipse also in the pattern?

– That we have a Total Lunar eclipse on a passover? The chances of a lunar eclipse happening on a specified date in any year is 1 in 365.25/1.437 which is 1 in 254.2. In other words, you can expect a lunar eclipse on Passover once every 254 years, on average if we count with solar years. In lunar years it would be 354.37/1.437=246.6. If we

– That the Tetrad falls on four Jewish holly days?

– That the Tetrad and the solar eclipse all falls on a jewish holidays?


04/15/2014 – Total Lunar Eclipse – Passover – 1ST High Sabbath of unleavened bread

10/08/2014 – Total Lunar Eclipse – Sukkot – 1ST High Sabbath of Tabernacles

03/20/2015 – Total Solar Eclipse – Adar 29, Nisan 1 – Civil New Year

04/04/2015 – Total Lunar Eclipse – Passover – 1ST High Sabbath of unleavened bread

09/28/2015 – Total Lunar Eclipse – Sukkot – 1ST High Sabbath of Tabernacles

Many thanks for your help



Many thanks for your input. I have just concluded the empirical examination of how many Tetrads we have on Hebrew holidays scince year 1 a.C until year 3000 a.C. The result is as follow: 3000 years / 9 = 333 years inbetween each one in avarage.

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8 Answers

  • 6 years ago
    Favourite answer

    Hmm, ..., that is quite interesting.

    All of the Lunar eclipses with be either fully or partially observable form the Eastern US. The Solar Eclipse (3/20/2015) Will occur over the North Atlantic between the UK and Iceland. It's unlikely that anyone will see it except Orca's, Whales, and those on specialized eclipse cruses. See Skymap Pro 6.0

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  • manfro
    Lv 4
    4 years ago

    Jewish Holidays 2014-15

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  • Thomas
    Lv 7
    6 years ago

    The Jewish calendar is itself based on the lunar cycle. So Passover and Sukkot are always at the full Moon, 1 Nisan is always a new Moon.

    For an eclipse, lunar or solar, to occur, the "nodes" of the Moon's orbit need to be lined up with the Sun. This "eclipse season" lasts for about 30 days, every 5 or 6 months, thus 'drifting' earlier each year. There will be two or three eclipses in each eclipse season.

    Since Sukkot is always 5 or 6 months before Passover, a whole bunch of lunar eclipses on both festivals over a couple of years is not at all unlikely.

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  • 6 years ago

    Only 3 tetrads have occurred in the last 500 years that are significant to Israel and also fall on the Jewish Feasts. We also know that these are the only tetrads that have a total solar eclipse somewhere within its series. The coming tetrad of 2014 and 2015 will also contain a total solar eclips within its series. What is different between the previous 3 tetrads significant to Israel and the coming tetrad is this series of 4 blood moons contains a Schemitah year beginning September 24, 2014 and concluding September 23, 2015. This Schemitah year year will begin on the first day of the Jewish New Year of 14 and conclude on the following celebration of the Jewish New Year in 2015.

    A tetrad with a total solar eclipse, historically significant to Israel and falling on the Jewish Feasts with a Schemitah year that corresponds with the Feast of Trumpets within its series is astronomically rare.

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  • Anonymous
    6 years ago

    Short answer: Better than 1/1000 on any given Passover and better than 1/100 in the 300 years beginning in 1901.

    The calculations in the original question are way off. I'm not going to pretend that a lunar tetrad on Passover and Sukkot is extremely common, but knowing some basic facts about the Jewish calendar and astronomy (and how to properly use statistics) will illustrate why it is far more common an occurrence than the person who asked this question suggests.

    First, the Jewish calendar is based on lunar cycles. This means that each month starts on a New Moon and therefor has a Full moon in the middle. Every single holy day that falls on the 15th of a given Jewish month is going to be a Full Moon. Both Passover and Sukkot are observed on the 15th day of a Jewish month (15 Nissan and 15 Tishrei respectively) so they ALWAYS fall on a full moon.

    A lunar eclipse can only happen on a full moon, of which about 30% are full lunar eclipses. There are anywhere from 0 to 4 full lunar eclipses in any given year. A lunar tetrad (four consecutive full eclipses) accounts for about 16% of all total lunar eclipses.

    The duration between full lunar eclipses in a tetrad is always 6 lunar cycles. Since the beginning of a Jewish month falls on the fist new moon, Passover and Sukkot are exactly 6 lunar cycles away from each other 82%(there are leap months every 19 years) of the time. This means that IF the any given Full Eclipse of a Tetrad falls on Passover or Sukkot, there is LITERALLY a 82% chance that the tetrad will fall on Passover and Sukkot two consecutive years.

    Since we know that, the only statistically relevant question is how often will a tetrad fall on Passover or Sukkot. Tetrads account for 16% of all Full Eclipses, and Full Eclipses account for 5.5% of all Full Moons. Given this, there is a 0.9% chance that any given Full Moon is part of a tetrad, and a 14% chance that that full moon is either on Passover or Sukkot.

    So based on this, the actual probability is better than 1/1000 that Passover and Sukkot will fall on a tetrad- but much better than that if you happen to be in one of the lucky centuries where there are several tetrads (a century can have anywhere from 0 tetrads up to 8). We will have 8 tetrads from 2001-2100, and we had 6 from 1901-2000. Given that lunar cycles are based on a discernible pattern it stands to reason that this "amazingly rare coincidence" might actually happen relatively frequently during one 400 year period and never happen again for several thousand years.

    To top it off, by definition a solar eclipse can only happen during a New Moon, which will 100% of the time fall on a minor holy day on the Jewish calendar. So if there is a tetrad, 100% of solar eclipses in either of those years will fall on a holy day.

    • endof days6 years agoReport

      Excellent analysis. Balanced and realistic.

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  • 6 years ago

    Are you saying this whole phenomena happens ever 333 years? The likllihood of the "four blood moons" happening on each successive jewish holiday happens every 333 years?

    I think that is too low, if you found out that the liklihood of one blood moon happening on a certain day. I believe you came up with something like 1/240 chance.

    Thus the probability for four successive happenings uses the multiply method. You multiply 240*240*240*240 to get the probability of each blood moon happening on a specific date. Thus your probability is 1/3.3 Billion.

    In summary, if your initial calculation is correct, that there is a 1/240 chance of one of these blood moons occurring on a specific date, the probability of all four happening on specified dates is one in 3.3Billion.

    The nice thing about this is we'll find out rather shortly if any of this is a big deal. We don't have to wait long!

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  • 6 years ago

    Is it just me or does anyone see alot of the 333's showing up? Maybe just me...but seems to be alot lol

    • Kathy6 years agoReport

      kg i've been seeing 333 for years, i asked another person i know did they ever see a number often the said 333, that blew me away.

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  • 6 years ago

    The odds are in the millions idk much about the Jewish holidays I'm so sorry. I have to say its unlikely though

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