What is the next Blue Moon?
A 鈥淥nce in a Blue Moon鈥 happens on Wednesday night, August 30. The Moon will not actually be the color blue, so don鈥檛 be disappointed. So, what is a Blue Moon, exactly? Read all about the different types of Blue Moons and tell us what you think.
What Is a Blue Moon?
Need a refresher on what a Blue Moon is? We get a lot of questions about the term, including:
- Is 鈥淏lue Moon鈥 a scientific term used in astronomy?
- Did this term originate with Native American folklore, like a number of the other full Moon names?
- Does a Blue Moon really look blue?
In truth, the answer to all of these questions is 鈥渘o.鈥
Read Next
The modern understanding of 鈥淏lue Moon鈥 only took off in the 1980s. It was a result of a much earlier mistake printed in a 1946 issue of Sky & Telescope magazine, and since then, the term has gone viral in the media.
Next Blue Moon on August 30, 2023
The next Blue Moon will occur on Wednesday, August 30, 2023.
This Blue Moon is also special because it鈥檚 the nearest supermoon of 2023. This means that this year鈥檚 Blue Moon is also the closest and brightest Moon of the year!
A Blue Moon and a Super Moon occuring on the same night happens roughly every 10 years, and won鈥檛 occur again for another 14 years, in the night sky in January and March 2037.
A Supermoon is when the Moon is at or near its closest point to Earth in its oval-shaped orbit. A super moon can also cause higher tides than usual.
Read more about the August full Moons here.
Two Types of Blue Moons
There are two definitions of the term though we commonly use the second term (a second full moon in one month).
- Seasonal Blue Moon: The extra full Moon that occurs within an astronomical season. One season鈥攄efined by the dates of the solstices and equinoxes鈥攖ypically has three full moons occurring within it. If a season instead has four full moons, then the third full moon (not the fourth) in the season may be called a Blue Moon.
- Calendrical Blue Moon: The second full moon to occur in a calendar month. It takes our Moon about 29.5 days to complete one cycle of phases (from new Moon to new Moon), so if a full Moon occurs on the first of a month, there will be a second full Moon鈥攁 Blue Moon鈥攁t the end of the month, too (except in February).
Although the latter definition is the one more commonly followed today, the former actually came first. As mentioned above, a misinterpretation of the seasonal definition in the 1940s gave way to the calendrical definition, which was later popularized in the 80s and has stuck around to today.
How Often Does a Blue Moon Occur?
Most months have one full Moon, not two.
Since the Moon鈥檚 period of phases is 29 1/2 days, while months usually have 30 or 31 days, it鈥檚 obvious that if a full Moon lands on the first day of any month except February, it will repeat again at the end.
Turns out, calendrical Blue Moons happen every 30 months on average. Two and a half years. Seasonal Blue Moons happen at a similar rate: about once every two to three years. So maybe 鈥淥nce in a Blue Moon鈥 isn鈥檛 so rare after all!
Two Blue Moons in a Single Year
How often do we have two Blue Moons in a single year? (As in 2018, when there were Blue Moons in both January and March and no full Moon in February.)
This won鈥檛 happen again until 2037, when we will again have another Blue Moon in both January and March.
Learn More
Want to learn more about the Moon? See the 蜜桃恋人鈥檚 Moon Phase Calendar and Full Moon Calendar!
Bob Berman
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It is quite normal if you use Binoculars ......
You might need New glasses ...!!
Aloha
础苍诲谤茅
See my comment, just above --
Bob
Last nights full moon did apear here,East tuscaloosa Co. Al. a light blue.Around * pm CDT. Yellow afew min. later. I think This is a rare phenomonom that sarted the term. I believe I have read of this. I feel the origonal use was based on this and had mothing to do with calender days. Also we are wasting valuble sleep time debating this. Good night. Still would like other coment if others have acully seen a blue moon.
Event for August to be seen through the telescope?
I took a excellent picture of the blue moon tonight. My grandchildren (the Twins)thought it was an actual blue moon, funny. Beautiful glow of brightness with the grayish crater to be seen. Can another event be seen in August through the telescope for the grand children?
I heard we won't see another one til 2018.
The song 'Blue Moon' was written in 1934 so the 1940's couldn't have been the source of the terminology.
I'm not sure that's what he's getting at. He's just saying that "Once in a Blue Moon" is now a common expression that means something rarely happens. But in the world of astronomy, a "Blue Moon" (the second full Moon in a month) is not really a rare event. It happens every 2 to 3 years. And it's also just a normal calendar thing since a moon cycle is about a day shorter than a calendar month.
I understood that the original calender was 13 months and when we went to a 12 month calender we had to have 2 moons in one month. But if it is every 2/1/2 years then that doesn't really make sense.
Maxine
I just read about the 19 year metonic moon cycle, that on July 31, 2015 there will be a blue moon, and every 19 years after that, this cycle will place a blue moon on July 31 (2034). But there was a blue moon on July 31, 2004- less than 19 years back. Was the 2004 blue moon special in some way that it was not part of this 19 year cycle? Can you please explain this to me?
