The Hermès Arceau L’Heure De La Lune With Lunar Meteorite Dial

For most of the history of the moonphase as a complication, it has had what is essentially a supporting role — it’s usually a fairly diffident feature on the dial, with the cutout often residing humbly inside a sundial which may also be devoted to something else, like a small seconds or a pointer date display. Post-Quartz Crisis, however, the moonphase complication has become at least in some quarters, a star (to make a feeble celestial joke) in its own right. In the last couple of decades, we have seen moonphase complications in an enormous variety — conventional moonphases, increasgingly high precision moonphases, spherical moonphases, and even more exotic variations including various planetaria and telluriums. One of the most spectacular examples is from Hermès — the Arceau L’Heure De La Lune.

The Arceau L’Heure De La Lune was introduced by Hermès at the 2019 edition of the SIHH and was very well received, and since then it has come out in several different variations, including a number of different meteor dial models. These are generally released in quite small numbers — in early 2019, for instance, Hermès announced five new dial variations, three of which featured meteor dials which are unusual even for meteor dials.

Typically, meteor dials are made from iron-nickel meteorites recovered from impact sites around the world although many watch companies rely on iron-nickel meteorite fragments from a couple of locations — Namibia, for fragments of the Gibeon meteorite, and Sweden for the Muonionalusta meteorite. (If you’re interested in a little brand product crossover, a very bright meteor is called a bolide, which is also the name of a bag designed by Hermès in the 1920s; in French, “bolide” means a fast racing car as well).

Generally speaking, meteorite dials exhibit more or less the same surface appearance — a pattern of intersecting crystal planes formed by the very large metal crystals inside the meteorite. These patterns are called Widmanstätten patterns and the crystals which are responsible for the patterns are the result of extremely slow cooling of the interior of an asteroid — it takes millions of years of slow cooling for the crystals to form, so if you see them inside a suspected meteorite it’s almost, you might say, an iron-clad guarantee that the rock is Not Of This World.

There are however other sources of meteorites than iron-nickel asteroids. Meteorites can come from other planets and heavenly bodies if a large meteor hits one of them hard enough to eject surface material into space, and meteorites can be found on the Earth which are of both lunar and Martian origin. These meteorites have very different internal structures — lunar meteorites have a mottled appearance which is the result of partial melting and mixing of lunar rocks by impactors, which can take place multiple times over hundreds of millions of years before something hits the Moon hard enough to send lunar meteors hurtling earthward. Hermès has made Arceau L’Heure De La Lune watches with meteorites from Mars and the Moon, as well as from meteorites of unknown origin found in the Sahara desert and having a moonphase complication with a piece of an actual extraterrestrial body as its dial, really drives home the otherworldly nature of the complication.

The Arceau L’Heure De La Lune watch has received critical as well as popular accolades — in 2019 a model with an iron-nickel meteorite dial walked away with the Calendar And Astronomy prize at that year’s Grand Prix Horlogerie de Genève. The moonphase complication takes up the entire dial, and consists of two stationary Moon disks, with two rotating satellite disks which cover and uncover each of the Moon disks over the course of a lunar month. One of the disks shows the time, and the other, the date. The gearing for the disks (the complication was designed by Jean-François Mojon, founder of Chronode SA, who has also done work for, among others, MB&F) is set up so that the two displays are always “right side up” — for instance, no matter where the time disk is on the dial, 12 is always uppermost.

The Moon disks — made of mother of pearl — were designed by Dimitri Rybaltchenko, who has designed scarfs for Hermés in the past and whose family has done so as well (his great-great-uncle, Philippe Ledoux, was one of the most famous Hermès scarf designers of all time) and it carries a very subtle equestrian motif in the form of a stylized representation of the winged horse, Pegasus. Hermès is strongly associated with equestrian sports and with good reason. The company’s first products were saddles and leather bridles; in 2019, Marion Larochette, then director of the equestrian workshop for the company, said, “For almost a century the horse was the only client for Hermès.”

Why two moon disks? The complication as Hermès has done it with just one Moon would have been problematic from a design standpoint, and, moreover, with two Moons, you can show how the Moon looks to viewers in both the Northern and Southern Hemispheres. In the Northern Hemisphere, starting with a New Moon, the shadow of the Earth appears to cross the Moon from left to right, but it’s the opposite in the Southern Hemisphere. The Northern Hemisphere view is shown by the lower of the two Moon disks, as the satellites move clockwise around the dial.

The Hermès Arceau L’Heure De La Lune is on the larger side, at 43mm in diameter, but I think there is no doubt whatsoever that it makes excellent use of the available real estate. The combination of astronomical complication and extraterrestrial dial is a compelling one. Having an actual piece of another world as the backdrop to the Moonphase complication makes the pleasure of observing the watch very concrete — a tangible reminder, on the wrist, of the dynamics of the heavens, and their actual substance as well.

Shop This Watch