On March 11th 2011, a massive 8.9 magnitude earthquake centered off the eastern coast of Japan destroyed hundreds of lives, set off a major tsunami that hit multiple continents. As Japan tries to get back on its feet again, and prevent a nuclear meltdown as we speak, some “smart” people blamed the “supermoon” phenomena for all this devastation.

So what is a supermoon anyway?

Its a loose concept based on the well known fact that the moon’s orbit is not perfect circle with the earth at its center. In reality the moon’s orbit is slightly elliptical. What this means for us is that the moon is closer to the earth on some days than others and consequently causes some degree of variation in tides on earth. However we can positively say that this disaster was not caused by the supermoon.

So who did it?

To answer this question, it is best to look at some lunar ephemeris data on the Moon. The table below shows how some data on moon rise, transit and set times, its equatorial coordinates etc. One of the quantities we are interested is the diameter. When any object comes close to the observer, it appears bigger and hence has a larger angular diameter. If we scan the data from 15-2-2011 to 12-3-2011, we can clearly see the moon comes closest to our planet on February 19th. That is more than a week away from the earthquake!

Moon
Date       RA  (J2000)  Dec  Const- Elonga-  Dia- Rise  Tran-   Set 
                             ella.  tion     meter      sit        
2011     h  m   s    o  '  "         mag     '    h  m   h  m   h  m
Feb 10   3:00:41.5 +20:14:58  Ari   -9.7    0.10  9h44m 17h29m  0h20m
    11   3:53:55.5 +22:27:18  Tau  -10.2   30.49  10h20m 18h20m  1h24m
    12   4:49:58.6 +23:32:05  Tau  -10.7   30.95  11h04m 19h13m  2h26m
    13   5:48:12.6 +23:18:06  Tau  -11.1   31.46  11h59m 20h10m  3h24m
    14   6:47:33.8 +21:38:44  Gem  -11.4   31.98  13h05m 21h07m  4h15m
    15   7:46:52.3 +18:34:37  Gem  -11.8   32.48  14h19m 22h04m  4h59m
    16   8:45:13.8 +14:14:56  Cnc  -12.2   32.91  15h39m 23h00m  5h36m
    17   9:42:14.7  +8:56:30  Leo  -12.6   33.21  17h00m 23h55m  6h07m
    18  10:38:02.7  +3:01:37  Sex  -12.6   33.35  18h23m --h--m  6h35m
    19  11:33:07.6  -3:04:49  Leo  -12.2   33.31  19h45m  0h49m  7h01m
    20  12:28:09.0  -8:58:01  Vir  -11.8   33.12  21h07m  1h43m  7h27m
    21  13:23:42.8 -14:15:21  Vir  -11.5   32.79  22h27m  2h36m  7h55m
    22  14:20:10.5 -18:37:54  Vir  -11.1   32.38  23h45m  3h31m  8h26m
    23  15:17:29.5 -21:51:24  Lib  -10.7   31.92  --h--m  4h27m  9h02m
    24  16:15:10.8 -23:47:11  Sco  -10.2   31.47  0h58m  5h23m  9h45m
    25  17:12:24.1 -24:22:36  Oph   -9.7   31.04  2h03m  6h19m 10h35m
    26  18:08:13.8 -23:40:48  Sgr   -9.1   30.66  2h58m  7h15m 11h33m
    27  19:01:55.0 -21:49:41  Sgr   -8.5   30.33  3h43m  8h07m 12h36m
    28  19:53:04.9 -19:00:02  Sgr   -7.8   30.05  4h20m  8h57m 13h41m
Mar  1  20:41:44.6 -15:23:53  Cap   -6.9   29.82  4h49m  9h44m 14h47m
     2  21:28:13.7 -11:13:13  Cap   -5.3   29.65  5h14m 10h28m 15h51m
     3  22:13:04.6  -6:39:26  Aqr   -2.6   29.52  5h36m 11h11m 16h55m
     4  22:56:56.0  -1:53:12  Psc    0.2   29.43  5h56m 11h52m 17h58m
     5  23:40:29.6  +2:55:24  Psc   -2.3   29.39  6h16m 12h32m 19h00m
     6   0:24:28.1  +7:36:32  Psc   -5.1   29.40  6h35m 13h13m 20h03m
     7   1:09:32.5 +12:00:18  Psc   -6.8   29.47  6h56m 13h55m 21h06m
     8   1:56:20.6 +15:56:24  Ari   -7.7   29.60  7h19m 14h39m 22h09m
     9   2:45:22.4 +19:13:55  Ari   -8.3   29.79  7h47m 15h25m 23h12m
    10   3:36:55.0 +21:41:23  Tau   -8.9   30.07  8h20m 16h13m --h--m
    11   4:30:55.9 +23:07:23  Tau   -9.5   30.41  9h00m 17h04m  0h14m
    12   5:26:59.7 +23:21:50  Tau  -10.0   30.84  9h49m 17h58m  1h12m

A similar tidal effect happens when the moon reaches its apogee (farthest point from earth). This however happened recently on March 5th. which was still 6 days away from the disaster. An extra phenomena occurs when the sun, earth and moon line up. The tides from this lineup are much more stronger than the ones we have been talking about so far.

This is especially true if the moon is at the perigee and is either in an new or full moon phase. The expected tidal forces would have been stronger than usual. This is exactly what “astrologers” term as a supermoon. However, the effect is not that big a deal as astrologers would like to make people believe.

However there is nothing unusual about this and these conditions happen frequently. Media frenzies caused by low standard journalism like these UK Daily Mail, have done nothing but fuel superstition, and we at the AAAD felt it was necessary to educate people about this.

On the internet, you will find many articles connecting supermoon occurances with natural disaster. As a fraternity of science, we should caution people that one or two “coincidental” occurrences should not be counted as evidence. If this was truly the case, then we could be certain 100% of the time, each supermoon should cause a massive natural disaster.