2016 is going to end with two straight months of so-called supermoons, and one of the biggest observable moons ever rises this week.

On Thursday, Nov. 10, a supermoon will be visible, weather permitting.

As NASA explains, because the Moon has an elliptical orbit which stays oriented around Earth as it goes around the sun, one side of the orbit – 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.

After the Nov. 14 super-supermoon, we’ll have another one on Dec. 14. There also was a supermoon on Oct. 14.

The full moon of Nov. 14 is not only the closest full moon of 2016 but also the closest full moon to date in the 21st century. The full moon won’t come this close to Earth again until Nov. 25, 2034. And it is the closest it has been since January 1948.

A supermoon, or perigee full moon can appear to be as much as 14% bigger and 30% brighter than an apogee full moon. However it’s not always easy to tell the difference, because of cloud cover and urban light pollution. So make sure to find a nice, dark and maybe romantic spot to watch this rare sight.