This Monday, November 14th will be quite the breathtaking sight for avid sky-watchers as the moon, dubbed “supermoon”, will be at its closest point to Earth in almost 70 years. What makes this supermoon so special is that there is this rare combination of the moon’s close distance to the Earth while also being in full phase.
What are the facts?
This supermoon surely will get more attention as it hasn’t been this close to Earth since 1948 and will pass within 216,486 miles of Earth’s surface, or 22,000 miles closer than it is normally. This event is called perigee. This happens because the moon orbits Earth on an elliptical orbit rather than a circular one.
Although, this supermoon sounds as if it is going to be an astonishing, once-of-a-lifetime occasion not to be missed, it will actually appear only 14 percent larger and 30 percent brighter than a full moon at apogee, which is when a full moon is at its furthest point from Earth. So, a casual glance of the moon may not look any different than normal.
An interesting phenomenon that will happen here on Earth will result in an unusually lower-than-normal low tide, followed about an unusually higher-than-normal high tide. This extreme tide is called the perigean spring tide and will exert 48 percent more tidal force on November 14th than during the spring tides near apogee.
Even though this event will officially happen on Monday night, right after sunset, sky-watchers in North America and locations east of the International Dateline will have a better view of this phenomenon on Sunday night as the moon will set less than three hours at its closest approach at 6:23 a.m. EST the following day. If you live in the western half of the United States or Canada, you will be some of the lucky few that will be able to see the moon at full phase just before it sets that morning.
To the casual, sky-watcher, the difference between the two days will be very subtle. So, if it is cloudy on Sunday, it can still be viewed on Monday. And, if you miss the unusual supermoon this year, you will need to wait for the next one in the year 2034.