A supermoon will be taking place on September 27th, which means a full moon will be visible when it is at the point in its orbit where it is closest to the Earth. However, as NASA explains, this is the first time in over 30 years that a lunar eclipse will be taking place at the exact same time. So in the evening on September 27th in the US, people will be able to view a total lunar eclipse of the largest moon we can see for over an hour.
As NASA’s Noah Petro, a deputy project scientist for the Lunar Reconnaissance Orbiter, says, the moon’s orbit around the Earth is not in a perfect circle, so there is a point during the year when it is the farthest away, called apogee, and another point when it is the closest, called perigee. During perigee, a full moon appears about 14% larger and 30% brighter than during apogee, which how the term “supermoon” came about.
During a lunar eclipse, the Earth’s shadow will cover the moon for moon for more than an hour, do to our planet passing directly in between it and the sun. As for the eclipse taking place on the same day as a supermoon, Petro notes that it’s just a matter of timing, and that every once in a while “all these things just falls into place.”
This is the first supermoon lunar eclipse since 1982, and the next isn’t going to happen until 2033. People in North and South America will be able to see the eclipse on the night of September 27th, while those in Europe and Africa can see it in the early morning of September 28th.
The total lunar eclipse will last for 1 hour and 12 minutes. The supermoon will be visible right after nightfall, while the Earth’s shadow will begin appear at 9:07 PM EDT, and the total eclipse will start at 10:11 PM.