November 14, 2016 might just be another Monday for all of us, but it’s a special day for the Earth-Moon relationship. That’s because there’s going to be an extra special supermoon, one that hasn’t happened since January 26, 1948 - that’s sixty-eight years! If you miss this one, you will have to wait until November 25, 2034 to catch a sighting as close as this. Highlights are-

  • Last such supermoon was 68 years ago
  • Next supermoon like this won’t be until 2034
  • Best time to see Monday’s supermoon is around twilight hours

What is a supermoon?

For the unaware, a supermoon happens because the Moon’s distance from Earth is constantly changing. You see, the Moon’s orbit is not a perfect circle but rather elliptical, which means it’s closer at some point, and then farther away a few weeks later. Plus, the Moon goes through phases – from new moon all the way to full moon – depending on the amount of light it receives from the Sun and its position.

When these two things – closest approach (the scientific term for it is perigee) and full moon – happen at the same time, we get a supermoon. If you’re interested, the technical term for a supermoon is “perigee-syzygy of the Earth-Moon-Sun system”, where syzygy means the straight-line configuration of the three celestial bodies.

The thing is, there is more than one prevalent definition for a supermoon. Some maintain that a supermoon occurs when the satellite’s centre is less than 360,000 kilometres (about 223,694 miles) from Earth’s centre. The average distance, by comparison, is 384,400 km (about 238,855 miles). By that logic, supermoons tend to happen every month or so. Others prefer a more exclusive definition – the time when the Moon is closest to Earth in its full moon cycle, a period of roughly 14 months. Going by that, we get a supermoon about once in a year.

The one taking place on Monday, November 14 around the world falls in the 14-month category. The Moon’s distance from Earth is going to be 356,509 km (about 221,524 miles), a bit more than it was in 1948 (356,461 km). According to NASA, the November 14 supermoon will be 14 percent wider and 30 percent brighter than it is at apogee (that’s the opposite of perigee, i.e. farthest from Earth).

The catch there is “at apogee”. The values above aren’t in comparison to your average full moon, but when it’s farthest from Earth, as this helpful graphic from TimeandDate.com tells us. Hence, it’s more honest to say that Monday’s supermoon (the best since 1948) is only really 7 percent wider and 15 percent brighter than average.

Still, it’s a great excuse to go out and look at the Moon. Assuming weather permits, the best time to enjoy a supermoon is when the Moon is just above the horizon, as it will appear bigger when compared to things on the horizon – buildings, mountains et cetera. Scientists call this effect the Moon illusion.

November 14 supermoon time in India, US East Coast, West Coast, and elsewhere

NASA says the Moon will be at perigee at 6:22am EST for those in the US. That equates to 4:52pm IST here in India, but it won’t be visible then as moonrise isn’t until sometime later around the country.

Here are the times for a bunch of places around the world:

  • New Delhi, India: perigee at 4:52pm, moonrise at 5:37pm
  • West Coast, USA (Los Angeles): perigee at 3:22am, moonrise at 5:29pm
  • East Cost, USA (New York): perigee at 6:22am, moonrise at 5:14pm
  • London, UK: perigee at 11:22am, moonrise at 4:44pm
  • Berlin, Germany: perigee at 12:22pm, moonrise at 4:46pm
  • Moscow, Russia: perigee at 2:22pm, moonrise at 4:56pm
  • Istanbul, Turkey: perigee at 2:22pm, moonrise at 6:08pm
  • Beijing, China: perigee at 7:22pm, moonrise at 5:09pm
  • Sydney, Australia: perigee at 10:22pm, moonrise at 7:07pm

All times for moonrise are according to TimeandDate.com

How to watch the November 14 supermoon live

Full moons rise around sunset, so if your place isn’t listed above, look east during the twilight hours to spot the supermoon at its best time. Your best bet is to, of course, look out the window. But if the weather is against you, you can find live streams on community observatory Slooh’s website, via a camera at the top of the Baraket Observatory’s dome in Israel, and the Virtual Telescope Project from Italy.

The post originally appeared at NDTV Gadgets.