# What (the heck) is a Super Worm Equinox Moon?

Google News feed shows me the following.

What does the term "Super Worm Equinox Moon" mean and has it ever been used before this 2019 clickbait instance?

• Not to be confused with Moon Worm. Mar 21, 2019 at 1:45
• They forgot to add in "Frosty" or "Fiery", depending on if the average temperature outside will be cool or warm. Should also be a Moon "of Doom" or "of Bountiful Tidings", depending on how the stock market's doing.
– Nat
Mar 21, 2019 at 7:33

All those adjectives being smooshed together signify an uncommon event. That's why you've never seen them together like that before.

All 3 conditions have to hold true:

1. It's a supermoon, which means the full moon coincides with the moons perigee or nearest approach. That can make it appear up to 30% brighter than one at apogee (farthest away). These happen about every 13 months and it doesn't have to be exact so usually, we get 2 of them in a row, like we did this year. February had a supermoon and so did March.

2. It's a worm moon, which means it is occurring in the month of March (see @astrosnapper's answer for a better explanation of that).

3. It's during an equinox, basically the first day of spring (or autumn).

If any one of those isn't happening then it can't be called a Super Worm Equinox Moon.

Apparently, the term supermoon (all one word, by the way) is a relatively recent thing. I tried to view it on Google N Gram viewer, but...

It is a particularly bright full moon and it does deserve to have its own terminology, IMO.

Update: The rarity of the event is certainly relative. I saw a tweet from National Geographic that we also had a super worm equinox moon 19 years ago.

• We don't see adjectives together like this very often because they don't serve as effective communication; they're just up at the moment as clickbait.
– Nat
Mar 21, 2019 at 7:25
• Condition two is rather unremarkable. March is guaranteed to have a full moon, and half of all equinoxes are in March.
Mar 21, 2019 at 7:40
• There are "rare events" in astronomy every other day, simply because there are so many combinations of celestial objects. Mar 21, 2019 at 8:11
• +1 While those might also all be valid statements, this answer is valid and straightforward, and addresses the question directly, and it reassures me that super worms are not going to appear during the full Moon at the equinox. Whew! That's a relief.
– uhoh
Mar 21, 2019 at 8:34
• @Octopus To be fair, your answer's accurate, and I'd ordinarily have $\texttt{+1}'\text{d}$ it for that. My objection was moreso in the phrasing that this is an "uncommon event". Not because that's wrong in a technical sense, but because it's misleading. I mean, say that we accept the premise that every snowflake is unique; then, each snowflake that falls in a snowstorm is a unique event, as the rarest of them all. But then should the media report stories about "rare" snowflake fallings? By the same token, this event may be "uncommon", but like the snowflakes, it seems misleading.
– Nat
Mar 21, 2019 at 22:19

All the monthly Full Moons are named e.g. list at timeanddate.com, of which "Harvest Moon" is the one people are probably most familiar with. So the March Full Moon is indeed the "Worm Moon" although rarely referred to as such. The extra hyperbole ("Super", "Blood" etc) seems to be a recent (within the last few years) media phenomenon for unknown reasons...

• I think "super" refers to the apparent size of the moon due to it being closer to Earth (since the orbit is not perfect and it is sometimes closer and sometimes farther)? And "blood" refers to the reddish color. Mar 21, 2019 at 4:11
• I agree, but it's at most a few % bigger if the Full Moon is close to perigee so hardly warrants the "Super". The Moon has also been doing this for millennia before the media decided on this recent "rebranding exercise" and I wish they would stop... Mar 21, 2019 at 5:33
• This answer does not answer the equinox part at all and incorrectly claims that super is a meaningless hyperbole (it does have a meaning, even if it's not all that significant) Mar 21, 2019 at 10:20
• @astro: it's at most a few % bigger According to Octopus's answer it is 30% brighter.
– TaW
Mar 21, 2019 at 12:00
• Over use leads to fatigue and to "super" becoming "normal" which leads to even more terms being added into the description to try and make the next Full Moon that's slightly closer brighter "extra, really super"... As this APOD shows the difference in appearance between the 2 extremes is very small and IMHO doesn't justify a "super" adjective for something that's barely noticeable. Too much media hype of something that most people would not notice risks alienating people ("is that it!?") leaving little reserve to push something really new & exciting Mar 21, 2019 at 23:54

A supermoon is when the full moon occurs at the time when the moon is at its closest point to us in its elliptical orbit. This means that the moon is slightly bigger (honestly, you wouldn't notice it unless you made careful comparisons) and a chunk brighter than normal full moons. Except that supermoons happen three or four times every year, so, actually, a supermoon is itself a pretty normal full moon.

In the last few years, the media seems to have latched onto these as EXCITING! EVENTS!, despite the fact that they account for about a quarter of all new moons. In the last year or so, perhaps they sensing that we have supermoon fatigue ("What, another one? There was a supermoon only a couple of months ago..."), they've started putting long chains of adjectives in front of the word "supermoon" to make it sound EVEN! MORE! EXCITING!!1! These adjectives mostly come from traditional names for each month's full moon, but they sound NEW! and EXCITING!! because we don't use them very often in the modern era.

• From what I've read, supermoons do not occur every three or four months. Are you sure about that bit? I could definitely be wrong Mar 22, 2019 at 0:41
• @user23502 See astronomy.stackexchange.com/questions/30080/… Mar 22, 2019 at 1:28
• @user23502 You could definitely be right, too. :-) Edited; thanks. Mar 22, 2019 at 9:46