I was just watching this Omega commercial and the narrator was going on about how it was the first watch to be worn on the moon, the original ‘Moon Watch’ and so on. So it got me thinking, what’s with all the hoopla, wouldn’t a bunch of Casios function just as well in the weightlessness of space? Is it a question of accuracy? Resilience?
afaik, any watch will work on the moon.
The only issue I can see is the LCD screen responsiveness possibly slowing down to uselessness if the watch got exceptionally cold, but this would have to really, really cold.
Plus the daytime temp can easily exceed 250 [sup]o[/sup]F, which is well above the normal operating range of typical consumer electronics, so at the least, I’d expect a severely diminished lifespan. Heat kills batteries as well. I’m sure it would run for a few days under the extremes found there, but not for any extended length of time.
Are we talking about a watch worn inside a spacesuit/spacecraft, or out in vacuum? All consumer electronic devices work properly inside a spacecraft. (The only exception I can think of right now is pendulum clocks.) Vacuum can cause some problems with consumer products:
[ul]
[li]Moving parts can freeze up because the vacuum causes the lubricant to evaporate[/li][li]Certain electronic parts (capacitors, batteries and maybe LCD panels?) contain fluids that leak when exposed to vacuum[/li][li]Without convective cooling, electronic components can overheat[/li][/ul]
I don’t think it would have to be that cold even. I’ve seen watch and cell phone LCDs almost crap out around freezing. They get real sluggish and dim.
My old LCD watch was useless at anything colder than about -20C or so. My quartz hand watch has functioned fine at -40 for several winters now.
" Would my digital watch work on the moon?"
Probably Not if it’s one of those Atomic watches, which are cool, they set the time automatically from the atomic time signal & have to be within 2000 miles of it.
Back in the olden days, before quartz watches were available, they used to be regulated by a little wheel on a spring. Then they figured out how they could use a mechanical tuning fork and an electronic circuit to make them more accurate. This was state of the art in the 1960s, when NASA evaluated what watch astronauts should wear. They decided on the Omega.
Later, quartz crystals were used, so the era of the tuning fork watch was short-lived. Omega got a lot of publicity out of NASA’s decision, and not surprisingly they’re still trying to milk it.
But if they are out of range they carry on working fine, they just don’t readjust themselves.
In a vaccuum. In photos of the moon astronauts, you can see the watch on the outside of their suit on a huge Velcro strap.
Here’s an Omega page on the moon watch. You can see the xtra-long strap there.
Here’s a very detailed page discussing the exact models that went in space. It’s mostly watch-nut talk, but the pictures are kind of cool.
This is the watch in question (still produced). IMO it’s the coolest looking watch out there, which is why one is in my wrist right now 
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I think scr4 has pointed out the dominant failure mode that any digital watch would undergo on the lunar surface. Very few (if any) modern digital watches have electrolytic capacitors or other fluid filled components besides their batteries. Most digital watches are now entirely integrated onto a single chip.
Common batteries would be prone to immediate outgassing of their internal liquids. LCD display failure due to temperature extremes would come next. Another failure mode no one has pointed out is exposure to hard radiation. Without earth’s intervening atmosphere, a digital watch’s integrated circuitry would take some pretty severe hits. I don’t recall any modern digital watches being radiation hardened.
Since I know next to nothing about watches and watch parts I have to ask: wouldn’t this hinder the Omega Moon Watch? Or are the parts operated differently?
Thanks for the replies so far everyone, keep 'em coming! 
This temperature refers to the maximum of the lunar surface. So unless you’re intending in burying your watch in a shallow grave once you’re there it’s irrelevant.
Quality mechanical watches like Omegas use jeweled bearings which need little or no lubrication.
That isn’t just the surface, that’s anythng exposed to the Sun with about the same reflectivity as the lunar surface. A watch isn’t just going to stay magically cool just because it’s not sitting on the ground.
“afaik, any watch will work on the moon.”
Nope. As far as I know, there has not been any international time zone set up for the moon, so your watch is never going to work. There is a large middle-pacific time zone that seems to be doing nothing except covering a few piddly islands, so I suggest using that one as “Lunar Standard Time”.
The biggest problem I see is pressurization/depressurization. If your watch isn’t made for it, going from 1 atm. to 0 would leave the watch case with a positive pressure, which (maybe, perhaps) could blow the face or the back off, or at least crack it.
Air bubbles in watch components could similarly cause problems. I think that my watch (rated to 100 meters), is both strong enough to withstand that, while not being so air-tight that a pressure imbalance exists for long.
OK. So if you’re intending lying out in the sun for two week while the lunar day reaches its noon with your watch in constant sunlight it might reach this temperature.
Actually, I think the time constant for heating a small object like a wristwatch should be in the order of tens of minutes, not weeks. I don’t think a watch would reach 250F though - it wouldn’t be in constant sunlight, and it would lose some heat through conduction. This article says the watches were tested at a maximum of 200F.