Mars timekeeping

[LABHOUSE]

It could be 24 hour time but go up to 24:39:37 to be the end of the day and then go to 0:00 aka midnight.

[Tex]

...Okay.

I believe that any Martian explorers will still keep to standard Earth 24-hour cycle, but interesting idea.

[Brotoro]

I expect Martian explorers will use clocks based on Mars day/night cycles (since they will want to work outside in the daytime). I also expect that they will have a 39 minute 37 second free time period right after midnight, and otherwise use our standard hours, minutes, and seconds.

It's the poor buggers in Mission Control back on Earth who want to stay in sync with the Martians' work schedules who will have to get used to sleeping on weird schedules.

[Nuke]

you could keep a 24 hour day where a mars hour is slightly longer than an earth hour, about 61.649475 minutes. or you could throw in a leap day in about every 36 days.

but if you are going to set up a permanent colony on mars, you might as well develop a proper mars clock and calender and just convert between earth time and mars time with math. local atomic time will become a thing. since atomic clocks on earth and mars will likely diverge.

[TerLoki]

Well considering ground controllers for the Mars rovers are already using Martian time here on Earth, then I don't see why astronauts wouldn't just go based on the length of a Martian day when actually on Mars.

[Capt. Hunt]

The current Mars missions already use a 24 hour sol. Hours, minutes and seconds are just adjusted to be 2.7% longer. Clocks of course are calibrated to local time at either the Martian Prime Meridian or at the landing sites.

Edited April 29, 2014 by Capt. Hunt

[Nikolai]

You might find this useful: http://pubs.giss.nasa.gov/docs/2000/2000_Allison_McEwen_1.pdf

I used it to create a Mars clock in Windows way back in oh-two, where you could click on a map and it would show you the "time of day" (or, more correctly, the "time of sol") at the location you clicked on. There's no concept of time zone -- noon is based on when, on average(*), the Sun is directly overhead at your particular longitude -- but it's a really good algorithm. I'm an electrical engineer by education, so I'd love to help you out if you want.

(*) Since Mars' orbit is elliptical, it might or might not correspond to when the Sun is actually directly overhead, depending on the time of year. This happens on Earth, too, but somewhat less.

[LABHOUSE]

Thanks for all the replies and a mars colony will go up called mars one www.mars-one.com

[SuperFastJellyfish]

Thanks for all the replies and a mars colony will go up called mars one www.mars-one.com

The reality of Mars One actually happening is broken down for you in this thread.

[RuBisCO]

The martian movie reminded me of this.

Back years ago on the mars one fan forum we had a productive discussion on this, here was the resulting ideas:

Summary: ultimately mars will need a timekeeping system all its own due to its day night cycle and seasons, humans in solar orbit or not on a world greater then an small asteroid could in theory operate just fine on earth time (Coordinated Universal Time). In the future it may be wise for humanity to put a coupled of atomic clocks in Earth-Sun L4/L5 for everyone in the solar system to synchronize their clocks too. After that each world would have their own clocks and clock system in theory.

Here are some suggested clock schemes for mars:

1. Use standard seconds, add a leap time after martian midnight of 39 m and 35.24 seconds. This is been proposed in several prominent science-fiction novels, the advantage is the hours and minutes are the same length as earth, the disadvantage is the dead time, especially what it would do for time zones. A midnight "witch hour" on one-side of mars is would be midday on the other side.

2. Use the standard second, change the hour and minutes. It turns out if we make a martian minute 67 seconds long, a martian hour 53 minutes long and a Sol 25 martian hours we can use the second to count a sol with only the need of .24 leap seconds per sol. Obviously these numbers are not as nice as the Sumerian base of 6 used for 60/60/24 earth time.

3. Change the second, keep everything else the same. By extending the second 2.7% a sol can be 60/60/24. This is what NASA presently uses to keep rover crew work schedules in sync with the rovers on mars, even to the point of having special watches with standard 12 hour dials but with clock work ticking at the slower martian seconds.

4. Change the second, introduce new time keeping units. The sky is the limit here, for example a decimals system can be used:

Hypothetical Mars Units / Earth Units

1 sol = 24 hours 39.5 minutes

decisol, desol = 2 hours 27.9 minutes

centisol, centol = 14.8 minutes

millisol, milol = 1.48 minutes

hectomicrosol, hectom, hectol = 8.88 seconds

decamicrosol, decam, dekol = 0.88 seconds

As you can see 100 dekols is a millisol, 1000 millisols is a sol. Seconds are important to many scientific units, and thus dekol or martian second (1.027 earth seconds) would not be a scientific measure. While such a system is very neat and metric it has to contend with the traditional appeal of 60/60/24 that we have all been trained with.

Calendar Time:

Martain weeks, months and years are different matter altogether from daytime or soltime keeping. A martian year has no formal name (I like "morb" or "sorb" as in "Martain Solar ORBit) neither do the mouths or weeks. If made of months, it would be closes to earth months at a martian year of 24 months, 28 sols long per month, with ever 6th month 27 days long with on of those shorten months having a leap day (27 to 28) roughly every other year. Thus a 7 sol long weeks would shift roughly one day every 6 months.

Alternatively we could just count sols but a 689 sol long year might get tiresome. At present though this is what rover teams do and they don't even reset per year, hence rovers are counting out at thousands of sols now.

Edited October 4, 2015 by RuBisCO

[How2FoldSoup]

Easy on the necro ReBi.

atomic clocks in Earth-Sun L4/L5

This wouldn't work. Due to relativity you would have these clocks disagreeing with clocks on both Mars and Earth quite quickly. You could do the math to convert using lorentz transform, but then what's the point of putting clocks in l4/l5 in the first place? Just keep them on Earth and convert from there.

[Camacha]

I believe that any Martian explorers will still keep to standard Earth 24-hour cycle, but interesting idea.

I cannot see that happening. A slowly shifting zero point is terrible if you are not living on Earth itself. The only workable option seems to be to accept the Martian day for what it is. How that is actually measured (translating the Mars rotational period to 24 units, adding time to an Earth clock, et cetera) is not very relevant beyond that and just a matter of convention.

[baggers]

Martian day: 24 martian hours seem practical and keep a good understanding between planets: you know your martian college will be at work from local 8-12; 13-17 for example. And yes, you cannot skype, but you can send a mail at office hours and expect a quick response.

Martian hour: 60 martian minutes of 60 martian seconds.

Convertion: Outlook will do that ^^

Physics: Earth second. (International System): you could have a special "earth second" option switch for your chronometer in class?

But for the "martian year", I think it's more practical to keep the "earth" year: so, everyone is in 2015 at about the same time, and can easily keep trace of birthdays, holydays... OK, spring and winter won't work well, but it don't matter: even on earth, holydays can be on spring or winter depending of your location.

But you will need to periodicaly "adjust" the martian calendar to keep it "on line" with earth years. A martian year is in that case 355,23 martians days, so a martian year is 355 days, and a bisextile every 4 years.

So, You have to choice 10 days to go off in the martian calendar. Or 10 "dual days": every 31 count as 30-31, maybe? ^^

[RuBisCO]

This wouldn't work. Due to relativity you would have these clocks disagreeing with clocks on both Mars and Earth quite quickly. You could do the math to convert using lorentz transform, but then what's the point of putting clocks in l4/l5 in the first place? Just keep them on Earth and convert from there.

Outside the gravity wells of a planet those clocks would in fact be a more accurate time pieces then any clock on earth or mars. The reason why a clock has to be put in L4/L5 is that Mars, or any other planet in fact does not always have line of sight with earth, because the sun is in the way, a relay station needs to be in L4/L5 if we expect uninterrupted communication with Mars, might as well put a timekeeper on it, because relaying a timesynch signal would added significant error.

[Kerbart]

NASA published a piece some time ago, in which they described how the crews in charge of the rover were kept on a Martian clock and it drove them absolutely nuts. Apparently our biological clock really can't handle days that are "a bit longer." -- it's like jetlag but then on a continueing basis (and any of you who has experienced real jetlag knows how bad it can be).

The conclusion of the article was that the concept of "we'll just adjust our clocks to the mars day" needs some serious reviewing and study because it's not that simple.

[baggers]

NASA published a piece some time ago, in which they described how the crews in charge of the rover were kept on a Martian clock and it drove them absolutely nuts. Apparently our biological clock really can't handle days that are "a bit longer." -- it's like jetlag but then on a continueing basis (and any of you who has experienced real jetlag knows how bad it can be).

The conclusion of the article was that the concept of "we'll just adjust our clocks to the mars day" needs some serious reviewing and study because it's not that simple.

A martian clock for a crew on Earth is a thing.

A martian clock for a crew on Mars is another thing.

For me, the conclusion of that experiment is that you can't work with Earth clock on Mars, like you can't work with Mars clock on Earth.

[RuBisCO]

NASA published a piece some time ago, in which they described how the crews in charge of the rover were kept on a Martian clock and it drove them absolutely nuts. Apparently our biological clock really can't handle days that are "a bit longer." -- it's like jetlag but then on a continueing basis (and any of you who has experienced real jetlag knows how bad it can be).

The conclusion of the article was that the concept of "we'll just adjust our clocks to the mars day" needs some serious reviewing and study because it's not that simple.

Was the article a scientific study? Because a scientific study says we can:

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0000721

I think in the case of mars rover controls that must constantly switch back to earth time to see their family or even leave JPL, yes that must be hectic. The idea that human's can't adapt to 24.6 hour days verse our natural cycle of 24.18, which is still off from an earth solar day, is unlikely.