The event is a “supermoon,” the closest and therefore the biggest and brightest full moon of the year. The moon will be about 221,802 miles from Earth. That’s about 15,300 miles closer than average.
According to experts that proximity will make the moon appear about 14 percent bigger than it would if the moon were at its farthest distance. They said that difference in appearance would be hard to observe with the unaided eye.
The moon’s distance from Earth varies because it follows an elliptical orbit rather than a circular one.
Like any full moon, the supermoon will look bigger when it’s on or near the horizon rather than higher in the sky, thanks to an optical illusion
The supermoon will bring unusually high tides because of its closeness and its alignment with the sun and Earth.