A penumbral lunar eclipse visible from south-west Russia. During a penumbral eclipse, the moon is ... [+]
You need to make a plan to watch the full Moon this fall because our satellite is about to do some interesting things.
This week a “Harvest Moon” will ring-in October. Towards the end of October—on Halloween, in fact—is the “Hunter’s Moon,” the second full Moon of the month. That also makes it a rare “Blue Moon,” at least by some definitions.
The “Halloween Hunter’s Blue Moon” is sure to be a big media event, but it won’t be the last in 2020.
Lastly this in this season is the “Frosty Moon,” another full Moon, but one with a difference. As seen from North America, November’s full Moon will be partially eclipsed by part of Earth’s shadow in space.
Here’s everything you need to know about the three full Moons of fall, including exactly when to look and what makes them so special:
How, when and where to watch a full Moon rising
All you need to do to see the “Harvest Moon,” the “Halloween Hunter’s Blue Moon” and the “Frosty Moon Eclipse” at their best is to find a low horizon to the east and be in place for the time of moonrise where you are. This incredible occurrence happens once every 29 days at a specific time, so don’t mess it up. Be patient and you’ll be treated to the sight of a gloriously huge-looking pale orange orb appearing on the horizon. Wow! It will then gradually change to yellow, and brighten, over the next 15 minutes or so before it finally becomes a white, bright orb that’s high in the sky.
1 – When is the ‘Harvest Moon?’
Date: Thursday, October 1, 2020
Best time to view: moonrise where you are
Why is the ‘Harvest Moon’ so late?
It’s perhaps the most famously-named full Moon of the entire year, but this year the “Harvest Moon” comes a little later than usual. It’s named after the full Moon that helps farmers get the crops in though the night; a full Moon always rises in the east at sunset and sinks in the west at sunrise. (Not that modern farmers tend to work at night!)
The “Harvest Moon” is typically the name for September’s full Moon, though technically it’s the full Moon that occurs closest to the autumn or fall equinox. That happened on September 22, 2020, making October 1, 2020’s full Moon the “Harvest Moon” this year. Last month was the “Corn Moon.”
The full Harvest moon rises over the ruins of St Michael's Church in Somerset, England.
How to see the ‘Harvest Moon’ and Mars
The first of two full Moons in October, the “Harvest Moon” comes with a little extra treat for patient moon-gazers. Hang around for an hour—or come back later—and you’ll see the bright planet Mars rise at more or less the same point on the horizon as the full Moon just did—due east.
2 – When is the ‘Halloween Hunter’s Blue Moon?’
Date: Saturday, October 31, 2020
Best times to view: moonrise where you are
What is a ‘Blue Moon?’
It won’t look blue, just be called blue. October’s full Moon is traditionally called the “Hunter’s Moon,” but while it retains that folk name it also gets another. By some popular definitions the second full Moon in a calendar month can be called a “Blue Moon,” as in the saying “once in a Blue Moon.” It’s not actually that rare, occurring about once every 2.5 years.
The full Moon from Lake Myvatn, northern Iceland.
Why is there a ‘Blue Moon’ on Halloween?
The lunar cycle means there’s a full Moon on every specific date every 19 years—there’s another “Halloween Blue Moon” in 2039—but calendar quirks mean that this will be the first full Moon on Halloween for all timezones of the US since 1944.
The happening of a full Moon on Halloween is largely meaningless, and yet it’s worth remembering that Halloween is actually an important date in our planet’s journey around the Sun. The date of October 31—also called All Hallow’s Eve—is a cross-quarter day that’s mid-way between the fall equinox and the solstice in December.
So the “Halloween Hunter’s Blue Moon” marks the middle of the astronomical season of fall.
3 – When is the ‘Frosty Moon Eclipse?’
Date: Monday, November 30, 2020
Best times to view: moonrise where you are and at 9:42 UTC—the point of greatest eclipse
What is a ‘Frosty Moon Eclipse?’
November’s full Moon is called the “Frosty Moon” or “Beaver Moon.” However, this one’s a bit special because it’s also going to be a penumbral lunar eclipse.
What is a penumbral lunar eclipse?
Lunar eclipses can only occur at full Moon, when our satellite is opposite the Sun with the Earth in between. The Earth’s shadow is always being projected into space, but because the Sun is so huge and the Earth relatively small, it’s a fuzzy circular shadow with a dense shadow at its center. When the Moon enters that central umbral shadow, it causes a total lunar eclipse, also called a “Blood Moon.”
However, that’s not what’s going to happen today. On November 30, 2020, the “Frosty Moon” will drift into Earth’s fuzzy penumbral shadow in space—that outer shadow–and cause a 2020’s fourth and final penumbral lunar eclipse. Essentially it will see some, but not all, of the sunlight that illuminates the Moon blocked by the Earth.
Image of the moon during a Penumbral Lunar Eclipse
What will the ‘Frosty Moon Eclipse’ look like?
Visible only from North and South America, Australia and East Asia, 83% of the full Moon will be covered by Earth’s penumbra. The greatest effect will be at maximum eclipse, which is at 9:42 UTC. That’s 4:42 a.m. in New York City; check the time where you live.
During the event the full Moon—while high in the night sky as seen from North America—will lose its brightness and become a dull grey. Not particularly exciting, perhaps, but it will look very strange to experienced moon-gazers—and it’s a wonderful chance to take a great photograph of our satellite, which is normally way too bright to image when in its full phase.
After these three full Moons of fall, the next one will be December 29’s “Cold Moon” ring-in a new astronomical season of winter.
Wishing you clear skies and wide eyes.
