Dr A P Bhat
Poornaprajna Amateur Astronomer's Club (PAAC)
Pics: Supplied
Udupi, Aug 8: If the clouds take mercy on us and keep away from blocking our view this Sunday, August 10, we can enjoy the phenomenon of supermoon. In terms of astronomy, this feature is known as Perigee or supermoon.
The orbital path of moon, which completes its rotation around the earth in about a month's time, is elliptic. The average radius of this orbit is 3,84,000 km. Therefore, once a month, moon comes very close to earth (3,56,000 km), and likewise, once a month, it also reaches the farthest point (4,06,000 km).
When it is in its closest point to the earth, the visibility of moon will be 14 percent greater than usual. It will also be about 30 percent brighter on this occasion. This increase in size and brightness becomes easily visible if that day happens to be full moon day.
Once in about 14 months time, moon comes closest to the earth on full moon day. On this day, the moon is known as supermoon. We get a chance to come across supermoon on August 10. The details of next supermoons are as follows:
August 10, 2014 – 3,56,898 km
September 28, 2015 – 3,56,879 km
November 14, 2016 – 3,56,523 km
January 2, 2018 – 3,56,605 km
Likewise, the moon appears smallest when it reaches the farthest point from the earth. The full moon day on which this phenomenon is observed, is known as micromoon. The next days of micromoon are March 5, 2015 (4,06,324 km), April 22, 2016 (4,06,248 km), and June 9, 2017 (4,06,268 km).
When moon comes closest to the earth on its orbital path, there can be changes in high tide and low tide of the sea because of change in gravitation. This will not be uniform in all places. Still, the affect of this phenomenon will not be more than a few inches. This change can also be noticed on supermoon day.
Moon has always been linked to dreams. Its existence gives rise to beautiful dreams. The wheel of movement from new moon day to full moon day continues to roll on, from month to month from darkness to light. Moon, with its silvery brightness on full moon day gives rise to a sense of unexplainable pleasure among humans. The earth appears to come alive on that day after bathing in the brightness of the moon, and the earth looks like having been soaked in milk.
Moon which changes in its brightness and size from day to day appears to be inviting you to witness what changes it goes through with each passing day. Wait for the sunset this Simday for the full-sized moon to lit up sky in the east. On that day, moon comes closer to earth by an average of 45,000 km.