5 things you need to know about Sunday's Supermoon eclipse

We are in for a rare celestial event this weekend. A total lunar eclipse will share the stage with a supermoon on Sunday night.

While you make plans to stay up late to watch the the night sky on this night, here are the 5 things you'll need to know about this event that won't happen again until 2033.

1) What is a Supermoon?

Supermoon was a term first coined in 1979 by astrologer Richard Nolle. While not considered an official astronomy term, it has seen a recent spike in popularity thanks in large part to social media sites, as well as local and national media outlets. There are only two requirements for a moon to be a Supermoon: first it must be in the full moon phase, and second the moon must be at its closest point to earth in its 27 day orbit cycle. When these occur together, the moon appears to be up to 14% bigger and up to 30% brighter as compared to its farthest point from earth. It is a misconception that a Supermoon is rare, as we can see them several times a year. Our last Supermoon occurred in late August, and the next and final Supermoon of this year will occur on October 27th.

2) A Rare Spectacle

While the Supermoon itself is not terribly rare, what is occurring this Sunday is indeed special. The moon will make its closest pass to earth, coming to just under 221,500 miles by Sunday night. In addition the moon will pass into the earth shadow around the same time, commonly known as a Lunar Eclipse. This is when the moon takes on a reddish tint, and is commonly referred to as a "blood moon." This combination of a Lunar Eclipse and Supermoon at the same time is a very rare spectacle. The last occurred 33 years ago in 1982 when Ronald Reagan was president, "E.T. the Extra-Terrestrial" hit movie theaters, and the great Michael Jackson released a little album called "Thriller." Do see it if you can, because this will be the last time these two events coincide for quite some time. The next "Blood Supermoon" will not occur for 17 more years, until 2033.

3) Are You Superstitious?

A lunar eclipse during a full moon, known as a "blood moon" due to the color the moon turns as it passes through the earth's shadow. This will also be the first full moon of autumn which is commonly referred to as the "harvest moon." There is a lot of folklore surrounding these two moons. Legends surrounding the "harvest moon" say that it brings earthquakes. Folklore on the "blood moon" is even darker, said to bring very bad luck and those who dare to sleep under it risked insanity or blindness. While science tells us that this Sunday will not be the end of the world, the moon will have some minor adverse effects on the coastlines. A full moon at its closest point to earth does bring slightly higher tides. With an approaching storm system from the south adding some gusty onshore winds as we head into the weekend, those of us in the weather department would not be shocked to see the coastal flood advisories already in place extended through the weekend.

4) Where and When Can I See It?

With most stargazing we recommend getting as far away from city lights as possible. However, with the Supermoon it is not as important. The moon itself will be bright and you can see it despite the city lights. The one recommendation is that that you get to high ground however, high enough to see over the clutter of the city buildings. To truly see it in all its brilliance however, you will need to get outside of town far away from the city lights. One recommendation is the Shenandoah National Park, which will be holding an event Sunday night to celebrate the occasion. There will be speakers from NASA and telescopes for stargazing. For more information, you can visit their website here. Moonrise on Sunday is at 6:49 p.m. with the Lunar Eclipse expected to start at 9:07 p.m. and peak at about 10:47 p.m. It will be fully viewable from all across the eastern United States as viewing conditions are good. This brings us to our final point…

5) Mother Nature May Not Cooperate…

We had nearly perfect weather for the Pope's visit to Washington D.C. this week, but as the old adage goes "nothing good lasts forever" and indeed this weekend will bring a change in the weather to D.C. A strong area of high pressure across New England has kept sun shining and the clouds at bay over the past few days. However, it is beginning to weaken and an area of low pressure will push in from the south to take its place, meaning a lot more in the way of clouds and perhaps even a few showers as we head into the weekend. Unfortunately our weather models are currently in good agreement that this area of low pressure is a slow mover, and Sunday night currently looks very cloudy. Despite the bleak forecast, there is a way you can still Sunday's moon extravaganza! NASA will be live streaming the entirety of the event on their website from observatories across the country beginning at 8 p.m. on Sunday. So even if the rain is falling outside, you can still view the Supermoon from the comfort of your own home!