What time is it on moon? Europe pushing for lunar time zone

https://apnews.com/article/moon-time-zone-space-2b0124415c14755e08a58e1b5ed5362a

by belter • 3 years ago

65 65 3 years ago

apnews.com

programmer_dude• 3 years ago

This title is a lot better than the last submission.

https://news.ycombinator.com/item?id=34982157

Galacta7• 3 years ago

For now, a moon mission runs on the time of the country that is operating the spacecraft.

Even more confusing since most spacefaring nations span across multiple time zones. Getting a lunar time zone that everyone can theoretically follow seems like a practical idea. It'll be interesting to see how this works on Mars, which would need to have its own planetary time zones (if there aren't already).

bcrosby95• 3 years ago

Timezones are a practical construct for humans. I'm not sure Mars needs its own planetary time zones until humans are living on it - I don't know what purpose it would otherwise serve.

WithinReason6• 3 years ago

Come on, even Earth doesn't need timezones.

goalieca• 3 years ago

Relativistic drift would be a thing over long distances and times.

monocasa• 3 years ago

Mars rover engineers already work on Mars local time interestingly enough. So right now there's functionally as many Mars time zones as there are current missions on the planet.

https://futurism.com/the-byte/nasa-scientists-live-work-mars...

mr_toad2• 3 years ago

Not just humans - if you have multiple agencies with multiple assets that need to interact then you need to agree on a common time.

xyzzy_plugh• 3 years ago

I have a difficult time reasoning about "local times" being more useful than say, UTC, for off-earth locations. The ISS used UTC and it feels right.

Sure, Mars is close enough to Earth that it could work, but the Moon takes 28 days to rotate. Other bodies have even more extreme cycles.

The article is light on details but I sure hope they're just talking UTC.

And for the record, local time can be very useful -- knowing when the sun is up will always have some value. E.g. exploration, agriculture, travel, energy. I just don't see how it works for humans to be human and communicate with other humans.

Xylakant2• 3 years ago

The issue is that time runs faster on the moon, so clocks will get out of sync, or you need to define a lunar second which will be different from an earth second. So pure UTC is not going to make it.

General relativity strikes again.

vlovich123• 3 years ago

A quick search yields 59 microseconds per day, right? That doesn’t seem significant at all for people to people interactions (21ms per year).

For automated systems that’s of course a different challenge and I think rather than clocks it may be useful to think about causality signatures if you’re comparing across the moon and earth. But even for automated systems, the time delay between earth and the moon is going to swamp 59 microseconds except for a minority of use cases that need ultra precise clocks that work across vastly different inertial frames.

Now for local operations on the moon? You probably don’t want UTC but that’s probably better established by sending scientists and engineers to the moon and letting them figure out what would make sense. Until then UTC is fine I think

amysox• 3 years ago

Definitely do not redefine the second. So many of our scientific units are based on the definition of a "second" as we see it on Earth, you'd throw everything into chaos. I believe one of the characters in The Moon is a Harsh Mistress pointed this out, as the newly-empowered Lunar government was considering redefining time to match the lunar day/night cycle.

(In that book, they certainly recognized "semi-lunars" reflecting the lunar day and night cycle, but, since Loonies, by and large, lived in pressure domes or underground, those didn't matter unless you were actually going to the surface. It definitely affected when people went out on the surface, why they went, and--because of the solar radiation hazard during bright semi-lunar--how long they stayed out.)

Consultant32452• 3 years ago

Remember that time we accidentally crashed a rover or something into Mars because someone forgot to convert their units? That was as hilarious as it was unfortunate.

PeterisP2• 3 years ago

There is literally zero need to have long-term tracking of "Moon time". For all long-term (day/week/year scale) you can work in whatever Earth time zone suits you best, and when the clocks will drift - no matter if that drift is due to relativity or plain old inaccuracy - just sync them to Earth time.

Yes, an isolated non-adjusted clock on the moon would have slowly accumulated some drift from the correct time, but who cares about that? For use cases which need extreme accuracy, do explicit adjustments for the time dilation in these specific conditions, just as we do for GPS satellites, instead of trying to define a single moon-wide lunar second or some offset from UTC.

dzhiurgis• 3 years ago

knowing when the sun is up will always have some value

Some, but it's terribly inaccurate - it varies by latitude and even midday can be off by 3 hours depending which part of country or autonomous zone you are in.

hinkley• 3 years ago

I could see a version of GMT where noon or mignight occur when your habitat is directly over the prime meridian.

But then the lunar days and hours wouldn’t line up with earth days.

jmclnx• 3 years ago

Why not use UTC ? On the moon, a time zone will be tough since each side of the moon is dark/light for about half a month.

elliottkember2• 3 years ago

I really hope someone has considered Daylight Savings Time on the moon.

valine• 3 years ago

There’s no need for daylight savings time on the moon. The day night cycle on the moon takes a month, and plus there’s no farmers up there yet.

elliottkember2• 3 years ago

Does the moon have seasons?

Edit: no seasons on the moon :(

downvotetruth4• 3 years ago

It's more about out competing the Nazi war production on the dark side.

torstenvl2• 3 years ago

Farmers have nothing to do with DST. Farmers don't live their lives by clocks anyway. Farmers universally think DST is stupid, and the ag industry is usually opposed.

https://nebraskapublicmedia.org/en/news/news-articles/not-a-...

fnordpiglet• 3 years ago

Absurd. Clearly we use Star dates off the earth.

_justinfunk• 3 years ago

Previously in the lunar time discussion: https://news.ycombinator.com/item?id=34525701

zokier2• 3 years ago

The ESA article gives much better rationale and explanation on what and why new timescale is needed, and why its relevant to define now: https://www.esa.int/Applications/Navigation/Telling_time_on_...

I'm slightly annoyed by media calling it time zone when the main focus is really on new time scale; I find it actually unlikely that timezones would be involved at least at this stage.

imoverclocked4• 3 years ago

I think a lot of comments are missing the idea that this is a single timezone, not many. The sun is always "up" on some side of the moon. Establishing a common time reference is for coordination of activities on the moon.

I imagine that the human-human verbiage with respect to sun angles might go something like, "at 2 MoonST the sun will be at a 4pm position for the rover and a 6pm position for the base. In two days, the sun will have moved about 1.7 hours later for both locations."

JohnFen3• 3 years ago

The sun is always "up" on some side of the moon.

I don't understand the relevance of this. The sun is always "up" on some side of the Earth, too.

imoverclocked4• 3 years ago

Many people equate timezone to mean a slice from pole to pole that has a similar Sun angle. If the moon has exactly one timezone, then that timezone describes the time on the entire surface and has no 1:1 analog with sun angle for a given spot within the timezone.

autokad• 3 years ago

I don't believe the moon has a dark side and light side. both sides get light / dark. The moon is locked with earth, not the sun. I could be wrong though

imoverclocked4• 3 years ago

Thats correct according to my understanding as well.

dekhn3• 3 years ago

the same part of the moon (the far side) always faces away from the earth as you say, and at any time, at least part of the moon is in shadow, which would be a "moving dark side"

wankle• 3 years ago

It's high time the Moon had a time zone. I own over 1000 acres I bought several years ago through the Lunar Embassy and it gets so confusing not having Moon standardized time.

jeron• 3 years ago

what do you plan to grow on those 1000 acres? Moon cheese?

webdevver• 3 years ago

But i thought the moon was already made of cheese!

mr_toad2• 3 years ago

Sounds about the right size for a lunar theme park.

donnowhy• 3 years ago

but the moon milk cows are at the moment getting decimated by the moon cheese lovers in a mad rush to make more pizza; they're at war!

it's a risky time to do moon business, there's even a faction that would get rid of the moon cuz it's not something they have back home and they don't get it

codehalo• 3 years ago

Moo Cheese.

downvotetruth4• 3 years ago

Lunar nightshades

torstenvl2• 3 years ago

Andy Weir answered this already. The moon is on Kenya time.

What time is it on moon? Europe pushing for lunar time zone

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