I talked about the events and festivals related to the coming full moon day, referred to as Kartik Poornima in hindu calendar in my last post . (Read it here: A full moon and a month full of festivals) But mark it, this full moon will also be a supermoon. It would be a an astronomical event that happened last time 68 years ago and will next happen only after 18 years.
‘Science Alert’ says that, “If you only see one astronomical event this year, make it the November supermoon, when the Moon will be the closest to Earth it’s been since January 1948.” During the event, which will happen on the eve of November 14, the Moon will appear up to 14 percent bigger and 30 percent brighter than an average full moon. This is the closest the Moon will get to Earth until 25 November 2034, so you really don’t want to miss this one.
So how do you get a supermoon?
As NASA explains, 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.
(See below couple of images from the last full moon on 16th October)
Supermoons aren’t all that uncommon – we just had one on October 16, and after the November 14 super-supermoon, we’ll have another one on December 14. But because the November 14 Moon becomes full within about 2 hours of perigee, it’s going to look the biggest it has in nearly seven decades. “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.”
Depending on where you’re viewing it from, the difference between a supermoon and a regular full moon can be stark, or difficult to tell. If the Moon is hanging high overhead, and you have no buildings or landmarks to compare it to, it can be tricky to tell that it’s larger than usual. (Budding photographers take note of it!)
See some striking images of 2014 supermoon from around the world-
But if you’re viewing from a spot where the Moon is sitting closer to the horizon, it can create what’s known as ‘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.”
Watch this video to know more about this year’s supermoon.