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Watch for this weekend’s supermoon

The December 3 full moon will be 2017’s 1st, last and only full supermoon. What that means. How to view it online.

Eliot Herman in Tucson, Arizona compared the apparent size of 2017’s smallest full moon in June with the November 2016 supermoon. He wrote: “Both images captured with a Questar telescope and a Nikon D800 camera. The images were combined with Photoshop.”

Full moon happens at the same instant worldwide on December 3, 2017 at 15:47 UTC; translate UTC to your time zone. It’ll be 2017’s first, last and only supermoon. In other words, this full moon will be near perigee, or the closest point of the moon in orbit for this month. Your eye probably can’t detect a difference in size between the December 3 supermoon and any ordinary full moon (although experienced observers say they can detect a size difference). But the supermoon is substantially brighter than an ordinary full moon.

Like every full moon, this one is opposite the sun from Earth. It’ll rise in the east as the sun sets in the west, ascend to its highest point in the sky in the middle of the night, and set in the west around dawn. Clouded out on December 3? The Virtual Telescope Project in Rome is offering an online viewing of the supermoon.

The December 2017 supermoon will be the first of three full moon supermoons in succession. The two full moons in January 2018 – on January 2 and 31 – also count as supermoons.

Some people will call the full moon on January 31 a Blue Moon because it’ll be the second of two full moons in one calendar month.

Moreover, the January 31, 2018 supermoon will stage a total eclipse of the moon: a super Blue Moon eclipse!

Read more about the December 2017 full supermoon.

Read more: What is a supermoon?

The Virtual Telescope Project in Rome, Italy will provide an online viewing of the December 3, 2017 supermoon, as it rises above Rome’s legendary monuments, with audio commentary by astrophysicist Gianluca Masi. Click here to join the show. The show starts December 3, 2017 at 16:00 UTC; translate UTC to your time zone.

As the moon orbits Earth, it changes phase in an orderly way. Follow these links to understand the various phases of the moon.

Four keys to understanding moon phases

Where’s the moon? Waxing crescent
Where’s the moon? First quarter
Where’s the moon? Waxing gibbous
What’s special about a full moon?
Where’s the moon? Waning gibbous
Where’s the moon? Last quarter
Where’s the moon? Waning crescent
Where’s the moon? New phase

Bottom line: A full moon looks full because it’s opposite Earth from the sun, showing us its fully lighted hemisphere or day side. The December 3, 2017 full moon is a supermoon.

Can you tell me the full moon names?

Moon in 2017: Phases, cycles, eclipses, supermoons and more

Deborah Byrd