Is There a Seasonal Blue Moon This Month?

This month, we have a "Blue Moon" on May 31, now popularly defined as a second Full Moon in a calendar month.  But there is also the traditional "Seasonal Blue Moon." 

To understand the complexities of the seasonal variety, you have to step away from our standard 12-month calendar and look at the year the way early astronomers, farmers, and religious officials did. They calculated by a year that was divided strictly by the solstices and equinoxes.

A true astronomical season is the three months between these celestial markers. For example, from the Summer Solstice in June to the Autumnal Equinox in September is the season of Summer.

Because a calendar season is three months long, it naturally contains three full moons. Each of these Full Moons historically had specific names based on folklore and agriculture—like the Harvest Moon, Hunter’s Moon, or Snow Moon—which helped people track planting, harvesting, and seasonal changes.

The lunar cycle (the time from one Full Moon to the next) lasts roughly 29.5 days. If you multiply that by three, a typical season takes about 88.5 days to complete. However, a calendar season is slightly longer, lasting roughly 91 to 92 days. Because of that small 3-day gap, the Full Moons slowly drift backward against the solar calendar. Every 2 to 3 years, the gap catches up, and four full moons manage to squeeze into a single season instead of the usual three.

Well, when a season contained four Full Moons, it created a major naming problem. If you just named them in order, the traditional names would get pushed out of sync with the actual seasons. For example, the "Harvest Moon" might suddenly occur too early, before the crops were actually ready to be brought in. 

To fix this, the Maine Farmers' Almanac introduced a clever rule: the third Full Moon in a four-moon season is designated the Blue Moon. By making the third one a wild card "Blue Moon," the fourth and final full moon of that season could keep its proper traditional name, keeping the rest of the calendar perfectly aligned for the upcoming year.

Complicated, right? 

Because this phenomenon relies on the alignment of the solar year and the lunar cycle, it follows a strict cosmic rhythm known as the Metonic Cycle. The Moon's phases repeat on the exact same calendar days every 19 years. During those 19 years, there are exactly 235 full moons but only 76 seasons. Do the math and you're left with 7 extra Full Moons. Therefore, a Seasonal Blue Moon occurs precisely 7 times every 19 years, making it a true astronomical rarity that perfectly embodies the phrase "once in a Blue Moon."

Men On the Moon

I remember watching Buzz Aldrin and Neil Armstrong set foot on our Moon on July 20, 1969. I was in high school but it was summer vacation so all of my friends had been outside being teenagers. But everyone went home to watch the astronauts.

I went home before 3 pm EST because that was supposed to be when they would be landing. I looked it up today and Apollo 11's Eagle lunar module landed at 20:17 GMT (3:17 my time) and then Neil Armstrong (who was closest to the door) was the first man to step on the Moon.

They landed in an area known as the Sea of Tranquility. When his feet touched the ground Armstrong spoke words that would become famous: “That’s one small step for man, one giant leap for mankind.” He later said that he had actually said “That’s one small step for a man” but the audio cut out and the “a" was lost. 

Buzz Aldrin called for a moment of silence shortly after the landing to give thanks for their survival. I read today but I don't recall that he took communion with a wafer and a tiny chalice of wine. 

Aldrin on the Moon in a photo by Armstrong, who can be seen reflected in Aldrin's visor.
NASA Image and Video Library</a>, Public Domain, Link

Buzz Aldrin grew up in Montclair, New Jersey, not far from my hometown. In 2016, his hometown middle school in Montclair was renamed Buzz Aldrin Middle School. I was the poet-in-the-schools person there for a few years. Students knew a bit about him - astronaut, Moon landing - but almost nothing about the actual landing or the space program. When I told them about watching the landing, they looked at me as if I was time traveler. I must be as old as their grandfather.

A teacher there told me that when they did the dedication Aldrin came to the school for an assembly and was kind of cranky and a bit "inappropriate" in his remarks to the pre-teens. Hey, he had been on the Moon!

The video from the Moon landing was not great quality by today's standards but the idea that it was coming from so far away made it amazing. Most people today still have no real understanding of how that picture appears on their Tv screen whether it travels by antenna, cable, or from their phone. 

I have to shake my head and wonder about people who still doubt that we ever landed on the Moon. There is something in humans that seems to be attracted to conspiracies and doubt. My favorite crazy theory is that director Stanley Kubrick did 2001: A Space Odyssey the year before. One source claims that Kubrick initially declined the offer, only relenting when NASA threatened to out his little brother as a member of the Communist Party. Knowing what I do about Kubrick, he would have had a hard time shooting bad video because he was so demanding as a director. 

That theory (which came mostly from one person and one book he wrote called held that Kubrick spent 18 months on a soundstage shooting the footage for the Apollo 11 and 12 Moon missions. Hey, in his 1980 film The Shining, the boy does wear an Apollo 11 sweater at one point. The 1978 film, Capricorn One, is about a journalist who uncovers a government hoax about astronauts landing on Mars. That prepares us for how they will fake the Mars landing one day.

I still look in wonder at the Moon most nights and it still seems incredible that we can send a spacecraft to the Moon or Mars. And how about that a telescope is now orbiting around the Sun at a distance of nearly 1 million miles (1.5 million kilometers) from Earth and sending back amazing photos of stars and planets? Using the JWST, we will be able to capture extremely distant galaxies as they were only 100 million years after the Big Bang – which happened around 13.8 billion years ago. We will be able to see light from 13.7 billion years ago. That must be fake too, right? 

The Phantom Galaxy NGC 628 as seen by the James Webb Space Telescope NASA/ESA/CSA/STSCI/JUDY SCHMIDT

The Moon, Jupiter and Spica

This Memorial Day Weekend, from May 25 to 28, we had some clear skies and some rainy ones. Tonight should be clear in my neighborhood and I will be able to see a very bright “star” near the moon. But it is not a star. It is Jupiter.

Venus sets in the west not too long after the sun had set, and the Moon and Jupiter were the two brightest objects in the sky.

I knew to look for a fainter true star. It is fainter but still one of the brightest stars, even in moon’s glare. This is Spica. It is the brightest star in the constellation Virgo the Maiden. I'm not very knowledgeable about the zodiac, but I know it is a key star in that study.

Spica is a first-magnitude star, but it appears much fainter than Jupiter. That is because Jupiter is relatively close (or at least nearer)to Earth. This is what draws me to gazing at the night sky is my semi-knowledgeable way: the idea that Spica is about 262 light-years away, and I am looking at its light.

The universe makes me think about the first meanings of words like WONDERful and AWEsome.

Spica is the easiest star to spot in Virgo. There is a saying to find Spica you can "follow the arc of the Big Dipper to Arcturus and speed on to Spica." But that probably doesn't make it any easier for the average Earthling to find because most people know very little about the night sky.

Besides Spica, other bright stars in Virgo include many I had never heard of: β Virginis (Zavijava), γ Virginis (Porrima), δ Virginis (Auva) and ε Virginis (Vindemiatrix). Other fainter stars that were also given names are ζ Virginis (Heze), η Virginis (Zaniah), ι Virginis (Syrma) and μ Virginis (Rijl al Awwa).

Again, the wonder and awe of all this is discovering that one of the stars, 70 Virginis, has one of the first known extrasolar planetary systems and it contains a confirmed planet 7.5 times the mass of Jupiter. I can't even really grasp the size of my own Earth. And the star Chi Virginis has one of the most massive planets ever detected, at a mass of 11.1 times that of Jupiter. And there are 35 verified exoplanets orbiting 29 stars in Virgo.

All this makes me feel like such a small part of the universe. But it makes me feel like part of he universe. I feel better knowing these things.

Leaving Our Mark On the Moon and Mars

Image via www.nasa.gov

On July 20, 1969, Neil Armstrong put his left foot on the rocky Moon. It was the first human footprint on the Moon. I recall seeing that Apollo 11 footprint photo many times back then.

The first footprints on the Moon will be there for a million years. There is no wind to blow them away. Two astronauts walked on the Moon and picked up rocks and dirt to bring back to Earth.

I don't know that I will still be blogging when humans put boots on Mars. Most estimates say that won't occur until the 2030s at the earliest. But we have already sent our robotic emissaries there and we have left our mark on the Red Planet.

There have been many landings on Mars. Some have have crashed and failed (Russia’s Mars 3 and Mars 6 landers, NASA’s Mars Polar Lander, the British Beagle 2) but they still sit there on Mars, gathering dust.

Curiosity rover’s tracks on Mars               Photo: NASA/JPL-Caltech/MSSS

Two survivors, the Opportunity and Curiosity rovers, are still at it. They are leaving their tracks as they roll across the planet. Opportunity is currently at 13 years. Pretty good considering it was a 3-month mission.

The larger and more sophisticated Curiosity is roving its way through the rugged terrain around Mt Sharp. As it moves, it is leaving a bit more than mere tracks. The engineers who built it included a secret message in the tread on its wheels. Curiosity’s wheels spell out J-P-L as they roll. JPL stands for the Jet Propulsion Lab, where the rover was created.