Up Close With The Supermoon
Tonight, the Moon will appear 14 percent larger and 30 percent brighter than usual full moons. And it all has to do with the proximity of the Earth to the moon.
“The full moon of November 14 is not only the closest full moon of 2016, but also the closest full moon to date in the 21st century,” says NASA.“The full moon won’t come this close to Earth again until 25 November 2034.”
NASA explains it here in some really scientific language: "because the Moon has an elliptical orbit, one side – called the perigee – is about 48,280 km (30,000 miles) closer to Earth than the other side (the apogee)."
"When the Sun, the Moon, and Earth line up as the Moon orbits Earth, that’s known as syzygy.
When this Earth-Moon-Sun system occurs with the perigee side of the Moon facing us, and the Moon happens to be on the opposite side of Earth from the Sun, we get what’s called a perigee-syzygy.
That causes the Moon to appear much bigger and brighter in our sky than usual, and it’s referred to as a Supermoon – or more technically, a perigee moon." -NASA
Sometimes even a Supermoon can look just like a regular full moon, and sometimes it can look enormous. When it looks really big, this is referred to as a "moon illusion."
“When the moon is near the horizon, it can look unnaturally large when viewed through trees, buildings, or other foreground objects,” says NASA. “The effect is an optical illusion, but that fact doesn’t take away from the experience.”