Despite many astronomers and the general public feeling a little fatigued by the high number of supermoon’s appearing this Summer, the final supermoon will be tonight. On the east coast of the US the moon will be visible in its largest form from around 9.38 pm.
A supermoon is a term thought to have been coined sometime in the 1980s and refers to a full moon that appears when the moon is at its closest point in orbit around the Earth. These events are thought to be rare enough to number between four and six supermoon events in each average year. However, 2014 seems to have been an unusually exciting year for astronomers of all kinds with three supermoon events occurring during July, August and September of this year.
The final supermoon of the Summer will also be a huge event for many as this full moon will coincide with the annual harvest moon, which is the full moon that occurs closest to the Autumn equinox. This years Autumn equinox falls on Sept 22 and will allow the supermoon to be viewed from across the US, if current weather patterns remain unchanged.
The supermoon does not have a definitive classification within the scientific community, but has recently become more well known as NASA and other astronomical groups have made the public aware of their appearance. NASA have even gone so far as to have explained how best to view a supermoon event, with the best view of the full moon in its closest orbit being reported when the moon is close to the horizon. When viewing the supermoon the moon will look unnaturally large when viewed through trees and buildings, with sky gazers in the deep south and New England currently given the best chance of seeing the moon at its fullest.
References: http://www.ksdk.com/story/life/2014/09/08/final-supermoon-2014-summer/15316113/