Super Moon Coming - on Chitra Pournami day

Today is Chitra Pournami – read its religious significance on my other blog.  Click here to read.   For ages, celestial objects have enthused the imagination of mankind.  We have all grown hearing various stories of moon – that beautiful round object on the clear night sky (on a full moon day). There are poets who have composed volumes and in olden day cinemas, hero and heroin under the influence of love would think of each other in moonlight and would start sing – when the rest of the World would be fast

Scientifically, it is another  “Supermoon” – Full Moon, New Moon, Waxing moon, Waning moon and …….. super moon ?  A "supermoon" is the coincidence of a full moon (or a new moon) with the closest approach the Moon makes to the Earth on its elliptical orbit, or perigee, leading to the technical name for a supermoon of the perigee-syzygy of the Earth-Moon-Sun system.  The perigee  (nearest point) full moon on May 5, 2012 will be as much as 14 percent bigger and 30 percent brighter than other full moons of 2012.   It is called a supermoon because this is a very noticeable alignment that at first glance would seem to have an effect. The 'super' in supermoon is really just the appearance of being closer.

To understand better, at  full moon, we are seeing all of the moon’s day side. The moon and sun are on a line, with Earth in between.

The Moon's distance varies each month between approximately 357,000 kilometers (222,000 mi) and 406,000 km (252,000 mi) due to its elliptical orbit around the Earth.  Today is significant. Today,  (May 5) at 11:35 p.m. EDT, the moon will officially turn full. And only 25 minutes later the moon will also arrive at perigee, its closest approach to Earth — a distance of 221,802 miles (356,955 kilometers) away.   In India, at  1 am on May 6, the full moon will be at 3,56,954 km from the centre of the earth. The moon will appear larger in the sky than at any time.   This will be the moon’s closest encounter with earth since March 19, 2011, when the moon was a scant 380 kilometers closer to earth. The next time a similar occurrence will take place is not until August 10, 2014.

There could doomsayers and predictions of ‘supermoon’ bringing natural disasters on its wake  - bad things happen to those who fear them and pessimists are eternally unhappy.   According to NASA, the effects on Earth from a supermoon are minor, and according to the most detailed studies by terrestrial seismologists and volcanologists, the combination of the moon being at its closest to Earth in its orbit, and being in its 'full moon' configuration (relative to the Earth and sun), should not affect the internal energy balance of the Earth since there are lunar tides every day. The Earth has stored a tremendous amount of internal energy within its thin outer shell or crust, and the small differences in the tidal forces exerted by the moon (and sun) are not enough to fundamentally overcome the much larger forces within the planet due to convection (and other aspects of the internal energy balance that drives plate tectonics).

It’s simply a phenomenon like any other full moon, added would be that  the supermoon will look bigger when it's on or near the horizon rather than higher in the sky, thanks to an optical illusion.  The supermoon will bring unusually high tides because of its closeness and its alignment with the sun and Earth, but the effect will be modest.  

Here are the Supermoons of last year, this year and 3 years to come and as you would observe, the difference is in hundreds of kilo meters and nothing to choose for a common man whose knowledge of celestial World is far too limited.

Year	Date	Distance
2011	19th Mar	356,575
2012	6th May	356,955
2013	23rd June	356,991
2014	10th Aug	356,896
2015	28th Sep	356,877

So tonight, look to the sky and simply enjoy !!

With regards – S. Sampathkumar.