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Number 2: Andreas Strehler Sauterelle à Lune Perpétuelle
Nudging out the younger Sarpaneva Lunations, Andreas Strehler released the Sauterelle à Lune Perpétuelle at Baselworld 2014 and in doing so created the watch with the most accurate moon phase ever up until that point. And he used only four extra components. Yikes!
![Sauterelle à Lune Perpétuelle fitting very nicely on the wrist of the yours truely](https://quillandpad.com/wp-content/uploads/2014/05/Andreas_Strehler_Sauterelle_a_Lune-Perpetuelle_7531.jpg)
Sauterelle à Lune Perpétuelle fitting very nicely on the wrist
It was a serious feat because the moon phase is being constantly driven. The moon phase utilizes internal and external gear teeth. And Strehler employed prime numbers for the teeth, creating very complex fractions and an accuracy bordering on insanity.
![Movement of the Sauterelle à Lune Perpétuelle by Andreas Strehler](https://quillandpad.com/wp-content/uploads/2014/05/Andreas_Strehler_Sauterelle_a_Lune-Perpetuelle_front.jpg)
Sauterelle à Lune Perpétuelle by Andreas Strehler
And just how insane is it? It will take 14,189.5383 years for the moon phase to be off by just one day!
For more information, please visit www.astrehler.ch/sauterelle-a-lune-perpetuelle.
Quick Facts Andreas Strehler Sauterelle à Lune Perpétuelle
Case: 41 x 10 mm, red gold or platinum
Movement: manually wound manufacture Calibre Sauterelle Lune Perpétuelle outfitted with remontoir d’égalité for constant force
Functions: hours, minutes, perpetual moon phase, which needs adjustment by one day only every 14,189.538 years
Price: CHF 96,000 plus applicable tax
But wait, there’s more!
The still reigning king of the moon phase is . . .
Number 1: Andreas Strehler Sauterelle à Lune Perpétuelle 2M, the most accurate moon phase ever in a wristwatch
So the story behind the Sauterelle à Lune Perpétuelle gets better. As Strehler presented his watch at Baselworld 2014, he also mentioned how he had written a computer program to calculate the gear teeth ratios to achieve the best accuracy he could.
As a side note, he mentioned that he actually had another ratio that was far more accurate than the one in the Sauterelle à Lune Perpétuelle, but it seemed almost crazy and overkill to put it into a watch.
A couple months later he did just that.
Utilizing the same number of parts and simply changing the ratios and number of teeth, Strehler was able to shatter the previous record and move into his own category: fundamentally perfect.
![](https://quillandpad.com/wp-content/uploads/2019/05/Andreas-Strehler_Sauterelle-2M_01.jpg)
Andreas Strehler Sauterelle à Lune Perpétuelle 2M
This new version of the watch has a moon phase 145 times more accurate than its own predecessor. The Sauterelle à Lune Perpétuelle 2M will be off by one single day after, get this, 2,060,757 years.
That’s not a typo: 2.06 million years!
This is such a long amount of time that the moon phase can be considered perfect, because by the time you would need to adjust it by one day. In 2.06 million years, the rotational period of the earth, the moon, and the relative orbits of both will have changed by such a degree that, because the moon is gradually moving away from the earth, our days will be about 36 seconds longer than they are now and every calculation will be null and void for multiple reasons.
So, basically, this is a perfect moon phase watch. It can’t be made any more perfect for the simple reason that the numbers involved in calculating it will change in less time than it requires adjusting the moon phase by a single day to be in sync again.
Boom!
*Andreas Strehler drops the mic and walks away*
*Cheers and applause, then silence*
*Andreas Strehler remembers something and picks up the mic again*
Of course Strehler is never one to let a good thing go, so he did what I previously said couldn’t be done, he made the perfect moon phase even more perfect. Not by changing the accuracy, that still is fundamentally perfect at 2.06 million years and anything more is probably the best definition of pointless. No, Strehler decided to make his moon phase utterly more easy to use and precise to set and adjust. Before the moon phase needed to be set based on the full moon or new moon position and then the time adjusted to get it as close as possible.
![](https://quillandpad.com/wp-content/uploads/2019/05/Andreas-Strehler-Sauterelle-a-Lune-Perpetuelle-Exact.jpg)
Andreas Strehler Lune Exacte
Strehler has since introduced a new watch named the Lune Exacte that features the same moon phase function but adds a Vernier scale to chart the age of the moon so that one can now adjust the moon phase to within three hours precision at any time throughout the synodic month.
The best bet for accuracy is still to set it based on the exact time of a full or new moon, but now you can set it nearly perfectly at any time throughout the month and then adjust perfectly at the top of the phase.
While it doesn’t add more accuracy to the mechanism it does add precision to the setting and adjustment of it, and the sheer usability of the mechanism for the average user. This means the Lune Exacte is tied for first place with the Sauterelle à Lune Perpétuelle 2M, but since the top three watches are all by Andreas Strehler, I’m guessing he won’t mind.
For more information, please visit www.astrehler.ch/sauterelle-a-lune-perpetuelle-2m.
Further reading: Blood Moons, Lunar Tetrads, And The Andreas Strehler Sauterelle A Lune Perpétuelle and Andreas Strehler Entered Into ‘Guinness Book Of World Records.’
Quick Facts Andreas Strehler Sauterelle à Lune Perpétuelle 2M
Case: 41 x 10 mm, red gold or platinum
Movement: manually wound manufacture Caliber Sauterelle Lune 2M outfitted with remontoir d’égalité for constant force; perpetual moon phase needing adjustment by one day only every 2.06 million years
Functions: hours, minutes, perpetual moon phase
Price: CHF 96,000 (red gold), CHF 113,000 (platinum)
Quick Facts Andreas Strehler Lune Exacte
Case: 41 x 10 mm, red gold or platinum
Movement: manually wound manufacture Caliber Sauterelle Lune Exacte outfitted with remontoir d’égalité for constant force; perpetual moon phase needing adjustment by one day only every 2.06 million years
Functions: hours, minutes; perpetual moon phase, age of moon scale
Price: CHF 112,000 (red gold), CHF 125,000 (platinum)
If moon phases interest you – and the chances are that if you have made it this far, then they do – you will probably love the moon phase app developed by Finnish independent watchmaker Stepan Sarpaneva, which is available free for both Android and iPhone.
* This article was first published on May 5, 2019 at The 10 Most Accurate Moon Phase Wristwatches Today (Plus Honorable Mention).
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