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Living on Mars Time
Roland Piquepaille writes "When NASA's rovers, 'Spirit' and 'Opportunity,' touch down on Mars next January, scientists and engineers in charge of the missions at the Jet Propulsion Laboratory (JPL), will start to experiment with a 90-day period of jet lag. Why? Because, as reports Astrobiology Magazine, 'a day on Mars is 39.5 minutes longer than a day on Earth.' To accommodate the requirements of interplanetary communication, during the mission the Spirit science and engineering teams will have to live on Mars time, in synch with the red planet's cycle of light and dark. This means that, here on Earth, they'll sometimes be working during daylight hours, and at other times they'll be working through the night. This summary contains more details and a screenshot of the Mars24 application, a Java program which gives you the time on Mars."
Have these people never had to work to a deadline before ???
:)
two words for them
JOLT COLA
Kingdom of Loathing (www.kingdomofloathing.com) Addicted is me
"Time to scoop up dust, analyze it and try to forget the fact that we pee through a tube."
"Oh."
A Java Application to display martian time? That sounds like a Java 101 excersise :)
Although the screenshots do look pretty neat.
Which is, of course, totally and completely different from what we do as computer people.
- In Capitalist America, law violates YOU!
Will they also be learning to live with the Terrible Secret of Space?
This means that, here on Earth, they'll sometimes be working during daylight hours, and at other times they'll be working through the night. :)
Oh my! I 'm allready living in mars time!
- Never underestimate the power of human stupidity.
Developed on Mac OS X. Cool! Seriously though, it will be interesting to see the engineers adjust to an ever changing schedule. And I thought 3rd shift was bad!
CDE open sourced! https://sourceforge.net/projects/cdesktopenv/
a day on Mars is 39.5 minutes longer than a day on Earth.
Great. This is a project-planner's fantasy. Forget offshore, we should move our software projects off-planet.
I once heard that, in test, the human body operates on a 25 hour cycle anyway, and we 'reset' our internal clocks ever day to fit in with the 24 hours of a day.
IIRC, tests were carried out where volunteers lived underground with no access to the outside world - no TV, windows, etc. They could call up to the surface to request books, games, food, but nothing that would allow them to work out any sence of time (no clocks either!). It was found that they reverted to a 25 hour day...
Shouldn't be too difficult for the scientists, or for colonization...
I don't see how this would be a problem. Several credible reports exist that say our natural body clock cycle is 25-26 hours, making the adjustment to "Mars time" rather painless.
Was that an attempt to a Dilbert-like humorous joke?
If so, please try again.
...When are going to switch to the "Stardate" notation of time?
Do not read this
Not everyone has a body clock that runs on an exact 24 hour cycle. Some people's circadian rhythms run as fast as 23 hours/cycle, some as slow as 25 hrs/cycle. JPL could test its employees for their natural cycle. A few days in a sleep test chamber quickly show which people tend to get up earlier and earlier each day vs. those that get up later and later. Then, they could selectively use people whose body clock matches that of Mars. Of course, I would still pity the families of the people that are on Mars time.
Two wrongs don't make a right, but three lefts do.
My understanding is that we (as in humans) are set up for a slightly longer day than 24 hours (I don't understand the science behind it). So perhaps it would be more appropriate for the crew to work to Mars time & the support team to *support* the people who are in a rather more stressful situation by working funny hours for a bit. Blimey, they can always record the Simpsons if they don't want to miss it.
But I wore the juice
Yes, I'm award the BBC report says 24 hours and 11 minutes. Still, it seems like as much of an adjustment living on strictly 24-hours as slightly more than 24 hours, 11 minutes.
Why? Changing the length of such a fundemental unit of time (other than one Planck unit of time) without changing its name is sure to cause confusion.
Not to mention, each measure of time will have to multiplied by a number not very much greater or smaller than 1, possibly causing precision problems, in order to convert it between Earth seconds and Mars seconds.
While I applaud the effort to make it easier to count time on Mars - I think, that in the bigger picture, it is not a good idea to use different fundemental units of time.
Even in the Clarke's 3001, the Ganymedes ignored the local time and measured the time in Earth units. If I recall correctly, they measured time with respect to UTC on Earth, completely ignoring local time.
A day thats still 24 hours long, but 39 minutes longer than an earth day? Is that Earth or Mars minutes now? We have enough problems (rockets blowing up etc.) caused by converting between the dissimilar metric and imperial units - who exactly thought redefining minutes and seconds to be slightly longer on mars was a good idea? Thats going to lead to something very expensive.
...lets not forget that the European Space Agency's Mars Express mission has almost reached the red planet, and that the British-built Beagle 2 probe onboard will be touching down on Christmas Day, to begin its search for life. I for one am very excited!
Tubal-Cain smokes the white owl.
'cause A Mars day helps you work, rest and play
A day on Mars, which is known as a "sol," consists of 24 hours, just like a day on Earth. Each hour contains 60 minutes; each minute 60 seconds. There's nothing magical about that. Scientists simply got together and declared it to be so. But there's a catch. A martian second is a smidge longer than what you're used to on Earth. Think of it this way: Instead of counting, "One Mississippi, two Mississippi" count "One Mississippis, two Mississippis."
yes, because redefining the basic elements by which we measure time is SOOOOO much simpler than making a Martian day 24 hours and 40 minutes long...
A meter is defined as distanced traveled by light in a vaccum in an amount of time, is a meter longer on mars now?
Im sure he doesnt have a boss anyway
Well, that dratted "24/7" slogan is definitely doomed on Mars.
Lots of people work alternating shifts that leave them with much worse schedules than this, and they get by fine. Or they go insane. No, I'm kidding. Seriously, a 40 minutes/day difference is nothing to adjust to. The hard part is just getting used to being awake and working at night if you haven't done it.
I personally work much better when I can actually see sunlight. Even cloudy days slow me down a bit (which is part of the reason I live 4 blocks from a caribbean beach in Mexico). But I've worked schedules worse than that for periods of months without any problem.
Mars Time????
Is that Metric or is that Imperial?
I mean.. like.. shouldnt they wait to see if it actually lands this time?
The More Knowledge you have the Luckier you Get- J.R. Ewing
I wonder what comparable effects (2 moons?) on Mars have led to both planets having similar days.
Or, is this just how the Designers planned this particular planetary system?
The Law of Falling Bodies
I wonder when they'll adopt the 'time slip' as suggested by Kim Stanley Robinson in 'Red Mars':
The day has 24 'official' hours; the 39+ extra minutes are, well, extra: party time!
Say out loud: I'm an Aspie and I'm somewhat proud, I guess. Uh. Can I write an email in all caps instead? Hm...
Oh, this is just a fancy, shmancy NASA way of solving the age old problem that there are not enough hours in the day.
But as several people have noted, this is not that different from what computer people deal with all the time. The major difference is that the NASA scientists get to go through a gradual transition from working in daylight to working at night. . . unlike winding down a 10+ hour day, only to find out a server is on the fritz and staying another 10+ trying to fix it.
This comment was generated by a squadron of trained super elite albino ninja chickens for you.
30 24 * * * /usr/bin/phone.home >/dev/null 2>&1
Just sleep in an extra 39 minutes every morning. It works for me!
One line blog. I hear that they're called Twitters now.
This is stupid. Submarines run on an 18 hour day and still manage to communicate very well with shore communications facilities, which use the standard 24 hour day.
Just an idle question: Why?
Is it because the probe is solar powered and has no batteries, so can't do any work at night, or because we can't talk to it when it's on the wrong side of mars?
Otherwise I'd have thought there'd be work to do all the time, so there's not much point in worrying about martian daylight time. We never went over to 28-day days for moon missions.
In soviet russia stale jokes recycle you!
actually, the rover has solar panels that do nothing but charge the onboard batteries. Since the power coming in from panels could go up or down, it makes much more sense to have the thing run off of batteries for a constant charge and then recharge the batteries with the solar cells.
Blaze a trail to the New World
10 hours a day, 100 minutes an hour, 100 seconds a minute. 1 day = 100000. 1 metric second = .864 "standard" (the prayer schedual of 13th century monks or something...) seconds. Should make for easy conversions between planets and such.
"Sic Semper Tyrannosaurus Rex."
Wow, that's almost enough time to fit in an extra episode of '24', especially if you cut out the commercials. Woo-hoo! More Elisha Cuthbert!
There have been lots of other posts about them changing the fundamental unit of time to do this, but what struck me is that they aren't using metric time. I would think that for a scientific endeavour such as this, where they are modifying the unit of time anyway, they would use a base-10 system instead of our current one.
This reminds me of an old issue of Astronomy magazine that contained instructions how to convert a normal (solar) digital clock into one that displayed siderial (star) time. It made use of the ability to switch between 50Hz and 60Hz AC operation.
Constitutionally Correct
I agree.
Frankly, given that we do all of our other work in base 10, I'm surprised scientists haven't used this as an opportunity to introduce a base-10 time system for mars (and the other planets as well).
1000 "metric seconds" (microsols) = 1 "metric minute" (millisol)
100 millisols = 1 "metric hour" (decisol)
10 decisols = 1 sol.
Convert between Martian time, Jupiter Time, Calliston Time, etc. via a simple coefficient (perhaps defined such that 1.0 yields earth standard time in base-10). Indeed, such a system could even be backported to the earth, should we ever have the desire. Given that the rest of our units of measure are in base 10, this makes perfect sense.
Of course, calendars do not lend themselves to base 10, but neither do they lend themselves to base 12 or base 60. In any event, that is no reason that basic temporal units, such as are used in physics (meters/second^2, etc) shouldn't be in the same base as the rest of our scientific units.
In addition to the easier kitchen-math of using base 10 over base 60, this approach would have had the added advantage of not being so easilly confusing: no one is going to confuse a second with a microsol, be it a microsol on Mars, on Jupiter, on Io, or even on Earth, while a 'martian second' vs. a 'terran second' is bound to sow all kinds of confusion over the next few generations.
The Future of Human Evolution: Autonomy
I remember in james gleick's excellent book "chaos" there's a story about mitchell feigenbaum doing a similar thing as an experiment. he tried adjusting his routine to a 26 hour cycle so his day moved in and out of phase with that of his co-workers at los alamos. if I remember correctly he gave it up becuase he found it too depressing having to get out of bed around sunset from time to time.
Lucky Marsians... that mean they get an extra 39 minutes per television season of "24!"
I hope that nobody will try to implement this on a mission to Mercury. The term 'a 90-day jetlag' might be a tad more appropriate in the Mercurian case than in the Martian case...
--
virve
Do you perform your best when you're exhausted, or even when you're just out of your routine? I know I flub routine stuff then -- or I spend energy remembering where I put my keys, so that the more challenging, more abstract stuff on my list gets less attention.
Maybe NASA needs to ask factories that have changing shift structures how they get things done, you know?
"Fundamentalism" isn't about divine morality. It's about human authority.
I like the solution to the time problem proposed in the Mars trilogy: ;)
unchanged minutes and hours, and 39.5 minuts dedicated to partying every day
Yes.
Perplexed scientists try to explain why every 33 days the rover Spirit goes on the fritz and craves chocolate.
Ergonomica Auctorita Illico!
The moon rises about 50 minutes later each day, and the tides occur later too. A few jobs that depend on the tides- fishing, seashore activities, walking across Venice without getting wet, etc.- will notice this change. Dont have to changew your sleep patterns like on Mars.
As some of the posters above have noted, the human body is not a happy camper when it comes to a 24-hour day.
In my humble opinion, that means we have a perfectly valid excuse to switching to metric time and measuring everything in seconds.;)
That is because the very intuitive duration of 100 kiloseconds is equal to slightly over 27 hours. That would give us an extra three hours of sleep or whatever else we would want in a day.:)
Metric time now!:P
Is this a sigs-optional kind of place? 'Cause I am totally down with that if you know what I mean.
The moon and its tides repeat on a 24 hour 48 minute periodicty. That could explain the 25 hour period in absence of light.
Its biologically useful to have multiple clocks. This spreads out activity cycles, so that short period disaster, e.g. predator, wont wipe out everyone.
During my thesis write-up I was basically working as much as I could before dropping dead. My day cycle went from 24 to 30 hours with a 20 hour working period followed by 10 hours sleep. I reckon I wasn't meant to live on this planet ;-)
Of course, there are some drawbacks... quite often I'd be eating pizza and watching the tellytubbies or some other crap on TV before going to bed at some crazy hour like 10AM, but sometimes I would show-up at the uni during "normal hours" even enjoying a pint or 2 with my mates after work. That day, I would just call "friday". Problem is, when your friday falls on a sunday, there aren't many mates to enjoy a pint after work... I guess there were "good" and "bad" fridays :-)
Did that for about 6 months until the viva. Took ages to go back into a 24 hour cycle and still now (2 years after) I have to be careful not to push it too much during weekends otherwise my sleep is basically screwed for the entire following week.
Sounds like NASA is up to no good and trying to force these people to work an extra 30+ minutes each day. i mean think about it. over the course of a year they will save millions :)
I spent much of my 20's & 30's (I'm an old fart now) working on 2 week shift rotations, through weekends and holidays. As if that weren't bad enough, we were expected to do software design, code & test on that kind of schedule. Humans can adapt to just about any straight shift, but if you want to see a bunch of zombies, put 'em on a rotation.
Just another day in Paradise
We need to switch to the metric time standard - centons microns....
People talk about this as though it were a new requirement, but some astronomers have done this before. I was involved in a project which used the old 300 foot telescope at Green Bank, WVA, which was only moveable in "longitude" -- for "latitude", we had to wait for our target to pass overhead. This meant we worked on sidereal time, but the cafeteria stayed on mean solar time. It was only a few minutes a day difference, but it was still pretty disruptive.
2*3*3*3*3*11*251
Kim Stanley Robinson, in his books Red Mars, Green Mars, and Blue Mars, had a really interesting system. Instead of keeping a 24 hour day and gradually getting out of sync w/ daylight, they add a 39 minute long "second" at midnight.
Did you mount a military-grade, variable-focus MASER on an unlicensed artificial intelligence?
...read "Man in His Time" by Brian Aldiss.
GET FREE APPLE STUFF!
Other than to perform a semi-interesting experiment for seeing how human beings on Mars would adjust to a slightly longer day, I do not understand the purpose for this. What do the operations of an orbiter and a rover have to do with this?
It's not like a shift change during an operation will mess things up. I mean the round-trip light time has got to be about an hour or so, right?
...will also be bombarded with radiation and have most of the oxygen removed.
What meaning does it have to say "the time on Mars"? What is the "time on earth"? It depends where you are... Have they defined time zones for the landers?
Pat
in his book Emergence: The Connected Lives of Ants, Brains, Cities, and Software, Steven Johnson says that, for some reason, human's internal clock is based on a day 25 hours long. this clock is reset every morning when you wake up. this explains why i tend to get tired an hour later each day, until i force myself to correct it.
this would probably mean living on Mars would feel more natural than on Earth.
We have to have a whole extra day every four years because a year is more than 365 days long. If we added a few minutes to every day to force a year to fit into 365 days, things would get confusing really fast. And you'd end up having sunrise at midday. It's a real shame that time isn't neatly packaged up in whole numbers for our small monkey-brains to digest easier. According to Einstein, time can move at different speeds in different parts of the universe, also depending on how fast you're moving relative to what you're using to measure time. And you're getting tripped up by this? This is KINDERGARTEN compared to the real problems in measuring time in this universe.
I ran a benchmark on my quantum computer, now I can't find it anywhere!
Of course, calendars do not lend themselves to base 10, but neither do they lend themselves to base 12 or base 60. In any event, that is no reason that basic temporal units, such as are used in physics (meters/second^2, etc) shouldn't be in the same base as the rest of our scientific units.
There's plenty of reason. Scientists prefer their choice of units to most naturally reflect the environment in which they're working. Kelvin is a more natural temperature scale for fundamental work, but Celsius, with 0 as freezing and 100 as boiling, is more natural in situations where water is important (like cooking and going outside). Particle physicists have one unit, the eV, which measures time, length, mass, etc. This wouldn't be particularly useful for measuring travel distance.
"86.4 ks from now" is not a useful way of refering to the same time tomorrow. This problem becomes much worse when you need to refer to several days away, since 0.7776 Ms is a horrible way to refer to 9 days. You might make the argument that the "day" is artificially chosen and not useful for measurement, but you would be sadly mistaken. For quite a while, at least, human life on this planet will revolve around a daily cycle. The sun still somewhat regulates our sleeping, and thus our work schedules.
If you try to remedy the problem by simply choosing the day as a fundamental unit and discarding the second, then you still run into the exact same problem we're discussing when you go to another planet. And even without interplanetary travel, you still have a problem when it comes to discussing years. Seasonal change affects our lives a great deal, so there is still value in maintaining a unit of time for a year.
Ugh. Any other Slashdotters want to contribute/correct me, please do :)
This has been proposed many, many times for use here on Earth. The metric-heads went gangbusters over it when Canada converted to metric back in the 70s, and it never took off, for obvious reasons:
Of course, calendars do not lend themselves to base 10, but neither do they lend themselves to base 12 or base 60
This here is the key. Our calender is (more or less) based on a logical observation of regular cyclical events in the sky. Our 12 months come from the cycle of the moon, of which we go through approximately 12 per year. The word "month" was originally "moonth", if you're curious. The problem, of course, is that nature didn't provide us with a nice 12 months of 30 days per month, so we have this hodepodge of units. We also don't have an exactly 365-day (which is base what, anyway?) year, but we manage, because measuring days is just about the most natural thing we can do.
As for minutes/seconds, this goes back to circular clock faces, and possibly sundials. I forget the exact mathematical reasoning behind it, but a circle just doesn't divide into base-100 nicely. Unless my professors just made this one up, or I'm remembering wrong, it's been a long time!
In short, the way we measure time is partly biological, and partly historical. I've managed to find pretty compelling reasons for most of it over the years, but yeah, like any measurement system, it's mostly arbitrary.
Endless arguments over trivial contradictions in books written by ignorant savages to explain thunder in the dark.
for years and years. The folks that man our nuclear subs live on an 18-hour cycle. For example, they get up a 7AM, stand watch from 8AM until 2PM, eat, shower (sometimes!), conduct maintenance, get some sleep, and then get up at 1AM. Then they stand watch from 2AM until 8AM, and so on. They do this for 2-3 months at a time.
Let me tell you, you get really, really tired at the end of this!
works on a 25h biological clock anyways.
There are only two possible explanations for this phenomenon:
I'd say either one strongly implies that aliens have been seriously messing with us before the advent of civilization. There are certainly many mythological cosmologies that feature humans arriving from somewhere else -- are there any that could be taken to imply a change in the Earth's orbit?
Set your base to accomodate pi?
They're called radians. They're the metric equivalent of degrees. They make geometry easy. Therefore our geometric overlords discourage their use.
They could be used for time, the base unit ("one-pi radian") would be half a revolution, or two Quarters. Of course all systems of time based on natural phenomena will have a problem with either years or days because they just don't add up. Therefore we need to change the Earth's orbit.
That second favorite of yours is no coincidence. It's just the inevitable result of two bodies orbiting each other.
You should read up on tidal locking, here, I'll get you started.
Quick link to 1st google result
"From my cold, dead hands you damn, dirty apes!" - CH
Why use "sols" which are, of course, highly variable, when we already have the metric unit "second"? Yes, seconds are rather arbitrary, but at least they're rigorously defined (by the decay of Cesium-133).
<aside>
I'd like to take this opportunity to propose changing the specification of a "second": one of the design goals (possibly back-specified) of the metric system is the ease of calculating the base units at home. So, in keeping with the SI obsession with water, I propose that the base unit of time be the length of time it takes for 1 litre of water to reach 100 Centigrade with the application of 1 newton of energy, or something like that...
</aside>
The problem with every system of proposed time is that it will either be inconvenient for days or years (as the Julian calendar is now), if nothing else. So I think our best bet is to change the Earth's orbit so revolutions are a round number. Actually, if the orbit was held at a fixed duration, then "sol" would be just fine as a unit.
Of course it's in Java; it avoids that pesky platform-dependent code problem... just switch to the Martian JVM!
I mean, who wants to work with
C'mon!
I've been living on slightly-longer than 24hr day for two years now.
It's just what my body is used to.
39.5 minutes... thats nothing. At times a will slip into 26 hour days for no reason what so ever. Only after a few days do I come out of my hole and realise I've lost one.
VENI, VIDI, VICI, DIXI
A) Complaints about redefining the second:
Days, seconds minutes, etc are all based on SOLAR cycles. We aren't redefining them, Mars' rotation is! We use UTC as that standard time unit and UTC is well defined, but it isn't linked to solar cycles on Mars so it's useless to keep track of Martian days with.
B) Complaints about why:
Read the article. The rover can only transmit at a time of day when the sun is up and Earth is in the sky. That is the same time of day on Mars every Martian day, but on Earth, due to the differences in rotation, shifts 39.5 minutes later each Earth day (no jokes please, you know what I mean). All NASA is saying is that mission controllers will need to do their jobs 39.5 minutes later each day because that's when the probe with be transmitting. It's not that hard to figure out! Yeesh.
You've been there too long when you start using the local calendar.
You're wrong.
Just because grads happen to give some significance to powers of ten doesn't automatically make them metric. They're far too arbitrary to enter the league of extraordinary units that is the SI.
To accommodate the requirements of
interplanetary communication, during the mission the Spirit science and engineering teams will have to
live on Mars time, in synch with the red planet's cycle of light and dark.
duh, we obviously need a fleet of deep space tdrs satellites.
Yeah, I totally sympathise with what you say. I also have a weird sleep system, because I work for myself too.
The only problem is that my pattern is nonexistant. I often sleep for 12 hours (20 being my record), and sometimes for just 4. I usually vary between 6 and 13. My waking time is also variable. Yesterday I was up for just 12 hours. Two days ago I was up for just 8. Four days ago I was up for 32.
I get the feeling this could cause me serious problems later.. but I just go to sleep when I feel tired, and wake up when I feel refreshed. And, well, this is the schedule God makes me run to!
mogorific carpentry experiments
Offtopic? Man.
I think some people may have no circadian cycles. I sleep a random number of hours, and am awake for a random number of hours each day.
This week's rough 'awake' hours have been like.. 32, 9, 29, 11, 17, 12.. and 'sleep' hours have been like.. 7, 4, 16, 11, 12, 6, 9.
I live quite easily in this situation (since I work for myself). Daylight appears to have no effect, unless I woke up at, say, 9pm.. in which case I usually have a wave of tiredness hit me when daylight comes.
Does this mean I have no rhythm, or a heavily distorted one?
mogorific carpentry experiments
... or they'll have a psychotic episode.
Don't blame me, I voted for Durga.
Can someone write an applet to help with out with my Venusian???
This means that, here on Earth, they'll sometimes be working during daylight hours, and at other times they'll be working through the night
... I think anyone with half a brain cell could've figured that out.
Well, duh
in girum imus nocte et consumimur igni
what ... i'm amazed no one mentioned him in this topic yet.
oh and personally, i found the 36 hour day very effective (At achieving nothing)
Sigs are for wimps. I am proud to be one.
I've I've always wondered about the fascination metric people have with base 10. Sure we have 10 fingers, but for ever other use 10 is a bad number system, it doesn't divide 3 or 4 easially, and you often need to do that in the real world.
Not that the other system of various bases is better for all purposes, but those units were often designed for the things you do with them. Things that are dividable by 3 are often divided into thirds, and so on.
I always thought the way that this extra 40 minutes was handled in Kim Stanley Robinson's Mars trilogy (Red Mars, Blue Mars, Green Mars) was great.I can't remember what they call that time period- but they just leave it off the clock. Every night at midnight, the transition from 12:00 AM to 12:01 AM takes 39.5 minutes rather than only 1. That way, you can go to bed later than you should've and still get a decent rest. :)
For any of you interested in Mars colonization, I highly reccomend the books. I've yet to read the last of the trilogy, but Red Mars was absolutely amazing. The second book was pretty good too, but it's hard to follow up something like the first. KSR portrays a very realistic near-future, and a lot of the technology it'd take in the book's version is already here. I think KSR serves on some various NASA committes regarding the future manned mission to Mars, etc.
Working toward a usable PDA environment in the spirit of Newton OS: Dynapad
I have to comment on another approach to Mars time. In Kim Stanley Robinson's Mars novels, which are otherwise well thought out, he uses this silly convention called a "Time Slip". At midnight, all clocks simply stop for 39 minutes and 30 seconds. Imagine the record keeping nightmares that would cause! Can't imagine was Robinson was thinking of, except maybe an infatuation with a certain Philip Dick novel. I never read it, but I assume it's as short on logic as most of Dick's work.
Put mission control on a boat and have it travel about one time zone per day.
for interplanetary missions. Since planets are in different reference frames and the cruise phase of an interplanetary mission takes a long time, there are relativistic effects in time keeping, though smaller than the differences in planetary rotation, are much more difficult to compute than the simple difference between days and sols.
The standard time used is normally the Barycentric Dynamical Time (or TDB), which is the time measured by a theoretical aomic clock placed at the barycenter of the solar system. Other time systems are used when needed. TDB is within 2 milliseconds of Terrestrial Dynamical Time (TDT, which is a similar time except computed for the Earth/Moon barycenter), which in turn differs from the more familiar UTC only in that TDT does not have leap seconds to account for variations in the angular velocity of Earth.
There is a standard library used in NASA missions called SPICE that handles these conversions between ephemeris times for planetary systems, spacecraft and TDB. It does a whole lot more (positions, speed and orientation of planetary objects and spacecraft, light travel time computations, etc.). The group that publishes this library is also responsible for publishing data files (called kernels, no relation to Unix) to facilitate these operations.
I wouldn't worry too much about time keeping differences. The only reason MER mission ops is concerned with this is because the rovers only operate in the Martian daytime. Time for missions is otherwise tracked using SCLK (spacecraft clock), SCET (space craft ephemeris time), or in TDB.
Here is a GPL PalmPilot port I wrote of Mars24 (using the actual time code, just a different UI):
MarsClock.
Space and Computers.
1000 "metric seconds" (microsols) = 1 "metric minute" (millisol)
100 millisols = 1 "metric hour" (decisol)
The use of the term "metric is not good even the divider is 10/100/1000.
To many the word "metric" translates as "normal" and "standardized". I propose that we will use the name "imperial hour" and "imperial minute" for that martian time.
It seems quite weird to me to stretch a second to make a day 24 hours. This will cause strange things, such as speed of light is a different value on Mars than on Earth though the speed is actually is equal of course.
At least it should NOT be called second/minute/hour etc !
The least inconvenient would to use the Greenwich time in all the Mars. This would require occasionally checking "at what time is the noon today?" but still that is the way of least trouble.
I've I've always wondered about the fascination metric people have with base 10. Sure we have 10 fingers, but for ever other use 10 is a bad number system, it doesn't divide 3 or 4 easially, and you often need to do that in the real world.
Because our numerical system and arithmatic is base 10, so using base ten units means conversion between units is simply a matter of moving the decimal point.
This is extremely useful, and works for every unit of measure EXCEPT time, which we have foolishly left in its archaic, hybrid form (base 12 hours, base 60 divisions thereof). Units of time, not to be confused with the calendar. The calendar will likely never be coherent, as planets, moons, and other celestial bodies rarely if ever choose orbits that are convinient to any human numbering system. But units of time that are typically used for calculating speed, acceleration, or duration of phenomena, are certainly amenable to a sensible approach, and one very elegant approach that scales to human sensibilities and biological cycles, and yet can be scaled to most measures of interest, is the day (or sol, if it is extraterrestrial).
When doing numerical calculations with standard units, one can move the decimal around (in ones head, if one is so inclined) to convert to or from any standard metric unit. This isn't true when switching from kph to kps, where instead of a sensible base 10 approach LIKE EVERY OTHER UNIT bar none, we have to use a base 60 multiplier, resulting in a multiplication by 3600.
Base 10 is more convinient, and dividing by 3 or 4 is no more difficult than for anything else in our decimal system.
Now, if you'd like to change the entire numerical system from base ten to base 12 or base 60, fine (I even postulate such a move in one of my novels), but as long as our numerical and arithmatic system is base 10, so too should be our units, including our basic units of time. This archaic, hybrid crap needs to go, and mapping that crap to another planet when there are far more elegant approaches (such as the one I outlined, not to mention numerous others) goes beyond absurd.
The Future of Human Evolution: Autonomy
This should be a breeze. I remember reading about a series of experiments where the subjects were denied any clues as to what the time was and they were found (in general) to fall fairly quickly into a 25-hour diurnal cycle. For some reason it appears our bodies are already attuned to a longer day than the Earth naturally provides.
;o)
Or maybe it's just that people love getting an extra hour in bed