What is Supermoon ? How does it affect our lives?

 

WHAT IS SUPERMOON ?

 

 

A supermoon is a full moon or a new moon that nearly coincides with perigee—the closest that the Moon comes to the Earth in its elliptic orbit—resulting in a slightly larger-than-usual apparent size of the lunar disk as viewed from Earth. . The term supermoon is astrological in origin and has no precise astronomical definition.supermoon" isn't a scientific term. By several accounts, it was first coined back in the late 1970s by an astrologer, Richard Nolle, who defined it as a new or full moon that occurs when the moon is within 90 percent of its closest approach to Earth in a given orbit — 224,641 miles or 361,524 kilometers from the planet. Given the change in distance between the moon’s farthest and closest points, the full moon can appear as much as 14% larger in the sky and 30% brighter to our eyes than at minimum size and brightness.

The technical name of Supermoon is a perigee syzygy (of the Earth–Moon–Sun system) or a full (or new) Moon around perigee .

WHAT CAUSES A SUPERMOON  ?

Supermoons happen because the moon doesn't orbit the earth in a perfect circle, but rather in an elliptical path. That means its distance from the Earth can vary in the course of a month, from 252,000 miles at its farthest point, which is called the apogee, to roughly 225,800 miles at its closest approach, which is called the perigee.
But the lunar orbit isn't perfectly regular, either, because it's affected by the sun's gravity. So on some occasions, the moon's perigee is closer than others.
Perigees happen on average every 29.53 days .

But a few times a year, the sun, moon and Earth line up just right, so that a perigee coincides with the most dramatic phases of the moon — the new moon, when the orb is just a sliver — or the full moon. That's when we notice because the moon can appear to be slightly bigger and significantly brighter than normal .



 

HOW DOES IT AFFECT OUR LIVES ?

Claims that supermoons can cause natural disasters, and the claim of Nolle that supermoons cause "geophysical stress", have been refuted by scientists.

Despite lack of scientific evidence, there has been media speculation that natural disasters, such as the 2011 Tōhoku earthquake and tsunami and the 2004 Indian Ocean earthquake and tsunami, are causally linked with the 1–2 week period surrounding a supermoon.A large, 7.5 magnitude earthquake centred 15 km north-east of Culverden, New Zealand at 00:03 NZDT on November 14, 2016, also coincided with a supermoon.

However Scientists have confirmed that the combined effect of the Sun and Moon on the Earth's oceans, the tide, is greatest when the Moon is either new or full.and that during lunar perigee, the tidal force is somewhat stronger, resulting in perigean spring tides. However, even at its most powerful, this force is still relatively weak, causing tidal differences of inches at most.

 

When the moon is closest to the Earth, its gravitational pull is at its peak.The variation from minimum lunar pull to maximum pull is roughly 23 percent. That sounds like a lot. However, it amounts to  less than 2000ths of the mass of the moon. The gravitational effect on a human being. Consider an 80-kilogram human being. The maximum difference between apogean and perigean moons is about 73 milligrams, or about 1/14th the mass of an ordinary paper clip.

If you factor in the solar gravity effect for a supermoon, or full moon closest to Earth, this effect may rise to about 110 milligrams, roughly equivalent to about 1/9th the mass of a paperclip.However moon do creates the tides. And an extra close moon can create higher-than-usual tides. But this doesn’t mean that an extra close new or full moon – a supermoon – has an effect on human beings.

 

 

 HOW CAN WE DIFFERENTIATE BETWEEN SUPERMOON AND REGULAR SIZED NEW MOON ?  

Well, the distinction between a supermoon (what astronomers call a lunar perigree) and a regular-sized moon isn't so great that it's obvious to everyone, especially if you're not a regular gazer at the skies. If you want to make the difference clearer, astronomy writer Bob King suggests fashioning a homemade measuring device that he calls a "supermoon sighter."

Take a pair of scissors, and cut a series of slots of varying widths in an index card. Then hold the card parallel to your face and at arms' length while looking at the moon with one eye, and pick the slot into which the moon fits most snugly. Mark the date next to it. Then, when you hear the announcement of the next supermoon, repeat the procedure, and you should be able to see the difference.