Super Moon 2018

The first full moon of 2018 will be a super moon

The first full moon of 2018 which will be on 2nd January 2018, will also be a super moon. This event will be somewhat different for the observers in India.

A super moon is that full moon which occurs when the moon is closest to Earth where the and Moon appears bigger and brighter.  A super moon appears about 14% bigger and about 30 % brighter than normal full moon as seen from Earth.  As Moon orbits round Earth in an elliptical orbit,  its distance from Earth keeps changing.  The closest point is called perigee and the farthest point in the orbit is called apogee.  In about one hour distance between Earth and Moon changes by about 667 k.m.

On Jan 2, Moon will reach its perigee at 3:34 a.m. that is, on the night of 1st of Jan 2018.  Its distance from Earth would be 356,565 k.m. and Moon will be 99.9% illuminated by sunlight. The full moon phase which comes just about 4.5 hours later on 2nd January 2018 is at 7:54 IST.  At that time Moon will be 356,846 k.m. from Earth.

Actually the best time to watch this super moon (or for that matter any full moon or Sun) would be when it is rising or setting, that is when Moon is closer to horizon.

Normally we are used to see full moon rising above the eastern horizon.  But this time (2nd Jan 18) it would be best to see Moon setting over western horizon in the early morning.

But if you missed this setting Moon then rising Moon on 2nd Jan would nearly be as beautiful.

The last super moon was the full moon of December 3, 2017.  It was not seen well from Mumbai as there were too many hazy clouds in the sky.

Images of Super moon of Dec 3, 2017, taken between two blinks of red light on the hi-rise building. Pictures are taken from Nehru Centre, Mumbai 

Super moon and Zero Shadow: Light of full moon is bright enough to cast a shadow.  On the night of 1st  Jan 2018, people living close to 20o  latitude will see the shadows of vertical objects disappear for a while as the moon passes overhead.  This is a Super Moon zero shadow.

Some of the places close to 20o  latitude, starting from east are Puri, Bhubaneshwar, Cuttack, Bhawanipatana,  Bhadravati, Chandrapur,  Pusad, Jalna, Aurangabad and Nashik.  Some places north and south of this line where one can feel the Moon overhead are Raipur, Durg, Nagpur, Yavatmal, Amravati, Bhusawal, Bid, Ahmednagar, Pune, Mumbai and Surat.  Please check the map below. The yellow line indicates the places where there would be a zero shadow due to Moon on the night of Jan 1, 2018


Moon illusion: Generally a rising moon (or sun) appears larger at the horizon than when it is well above the horizon. This effect is termed as moon illusion. However, there is no clear scientific understanding for this moon illusion. It is said that moon appears larger because we compare it with terrestrial objects such trees or buildings.   But people have had this illusion when there is nothing to compare Moon with such as during sea voyage.  The illusion also changes from person to person. Some people perceive rising moon twice as large and some none at all.

Interestingly, if one stands with their back to the rising Moon and bends down to see Moon from between one’s legs, the illusion disappears.