Shabbat (and other times) on Mars

[cellio]

I was recently asked about this, and I don't know what the current thinking is.

The question of when an astronaut observes Shabbat (while in space) is well-understood. [1] But what happens when we colonize other planets and your hometown is on Mars? Do you count six Mars-days and observe the seventh as Shabbat? How long is a month (and how do you decide which moon)? Is it still desirable to stay in sync with Earthly seasons, or will that go out the window? If you follow the sun as locally experienced, what happens when that causes hardship? (Does the lunar colony observe one ~29-day Shabbat every seven months?) There must be commentary on this by now from sources other than Wandering Stars, but I don't know what the popular opinion is.

[1] I know of three opinions for the astronaut in space: follow your hometown, follow the city from which you launched (your port of departure, like for ships), or follow Jerusalem. All of these involve a ~25-hour Shabbat every seven days, like on Earth, even though your orbit might cause you to see a 90-minute day. But the astronaut is, by definition, just visiting.

Comments

[geekosaur]

Also, what direction do the shuls point? Especially considering that (a) Earth could be at any angle within 4π steradians, and (b) the angle will probably change over centuries.

[cellio]

Up? :-)

I don't know. Would someone establish a "local" (planetary) proxy for Jerusalem and say "point here"? Or would the custom fade?

[geekosaur]

Quite possibly the custom would fade, if I'm remembering correctly about it being recent. After all, the Sages already have an all-purpose fallback: "direct your heart (to pray) toward Jerusalem", even if you don't know what physical direction it's in.

[chaos-wrangler.livejournal.com]

My dad used to point out that in the 4 or so rooms in a local shul that were used regularly for minyanim, only the beginners' minyan faced east. All the minyanim faced towards their respective arks, but the choice of location for each ark was based on room/building architecture more than anything else.

[geekosaur]

I have a recollection of hearing on KMTT that the whole thing about shuls pointing east, or more correctly toward Jerusalem, is actually a fairly recent conceit — only a couple hundred years old.

[grouchyoldcoot.livejournal.com]

Whatever rule you come up with should also apply to this new earth-like planet, of course, with a 19 (?) day year.

[tidesong.livejournal.com]

Wow, I never even thought about that! It kind of hurts my head. :D

(I am meeting with a Rabbi for the first time next week....)

[cellio]

Good luck with the meeting.

Err, I wouldn't open with questions about Shabbat on Mars. :-)

[siderea]

Does the lunar colony observe one ~29-day Shabbat every seven months?

Isn't doing that called "Islam"? ;)

[cellio]

Islam would have the same problems, but without the seasonal constraints. (They do a strictly-lunar calendar, so holidays move around in the year. The Jewish calendar is solar-adjusted so, e.g., Pesach stays in the spring. It's done with leap months, not leap days.)

If lunar days = legal days, Ramadan would be really rough -- which presumably would motivate them to find a different interpretation. :-)

[goljerp]

I'd say the answer depends upon what the locals do for time.

I'd guess that a lunar colony would use 24-hour earth time, since the Lunar days wouldn't make much sense. In that case, it's easy -- use the start/end times for shabbat in the largest (or most convenient) city with a Jewish population in the timezone the colony uses.

Mars, now, is tricky. The Mars day is just a bit more than 25 hours, right? If the colony starts keeping "Mars days", then Shabbat would have to be every 7th day, or else you'd have wacky things like starting shabbat at noon, local time. The problem then becomes that the calendar for Jews on Mars would start to drift... so I dunno. Maybe it could be solved by removing some of the 2-day rosh chodeshes?

I'd also hope that fasts wouldn't end up being significantly longer than on Earth.

Of course, all this is just off the top of my head, and I am not a Rabbi.

[mabfan.livejournal.com]

I asked a rabbi once about Mars for a novel I was writing. He said to have the Jews keep the Hebrew calendar on the colony ship in sync with Earth, and then once they land on Mars start counting their calendar from that Hebrew day, but use the Martian days instead. Yes, they'd get out of sync with the Jews on Earth, but he said that it was one legitimate way to solve the problem.

[wrenb.livejournal.com]

Similar to the way that certain festivals lengthened in the Diaspora due to moon-sightings in Jerusalem being a long way off? Makes sense to me.

[cellio]

That makes sense for days. What would they do about the year? Adjust the number of months to line up with a Martian year, or continue to have 12 (or 13) months of 29 (or 30) days like on Earth? If they're already out of sync with Earth that doesn't seem like a big deal, but that level of calendar reform would be major, too.

And... which moon governs months?

[530nm330hz.livejournal.com]

I know of three opinions for the astronaut in space: follow your hometown....

Which is what my rabbi told me to do when I spent a summer in Barrow, Alaska, and sunset was Aug. 4

[cellio]

He had you use your hometown rather than the closest Jewish community that actually has (daily) sunset? Interesting. I assume that's because you intended to be there temporarily, and that if you were moving there the answer would be different.

[530nm330hz.livejournal.com]

Yes. If I were moving there, he said the answer would be to follow Vancouver's times.

[ynyr.livejournal.com]

Yeah, and what would you do about some of the things you need for special festivals? And for Sukkot, where would you put the Sukkah? Wouldn't the entire area be enclosed? Would that be like building a Sukkah indoors?
What an interesting question.
Ynyr

[zevabe.livejournal.com]

If the sukkah needed to be outside of the little air-dome or whatever, everyone would be patur(exempt) as a mitztaer (lack of oxygen sure sounds like suffering to me). If they then wanted to build a sukkah in the air-dome, why not? I can see an issue of bal tosif (adding mitzvot, and doing one you are exempt from seems a good example) perhaps.

[geekosaur]

Completely winging it — I suspect the air dome would not be considered "indoors" in such a case, but either an eruv or equivalent to a walled city.

[baron-steffan.livejournal.com]

It's a fascinating question, and one that I've considered in the past (mostly from SF inclinations). My first impulse is to wonder if it's legitimate to consider that from a Biblical point of view, so to speak, if you're on Mars, you're in Heaven. 'Course, that opens a theological can of worms that's rather terrifying to contemplate, doesn't it?

How far do you suppose one can stretch the concept of "following local customs" to include a calendar so ferociously out of whack with anything terrestrial?

And one might have to consider the nature of the local civil calendar itself. How do you deal with observing shabbat when the local civil calendar has, let's say, 10 months, each consisting of six 9-local-day weeks of 17-local-hour days? I'm not talking about direct astronomical matters, but a civil/legal/administrative structure developed in response to the local astronomical situation...if that makes sense. How do you manage to be observant when shabbat starts this Tuesday at 14:17 am, and the next one is 11 (local) days later, and the one after that starts at half-past-27 on Zorgday the 39th? On Earth, you at least have a situation where Shabbat is always on Saturday.

When Jews travelled, as they always have, they always observed Shabbat by local time. Surely originally this was without regard to any knowledge that their observance was not actually taking place simultaneously with Jerusalem. But certainly such knowledge didn't take modern science to determine, astronomy being a very ancient and extremely sophisticated science, after all. So clearly the rule has always been to observe the times and seasons according to local conditions, as it were. And Genesis sets forth quite clearly the definition of a day: "and there was evening and there was morning". So, if you consider yourself to be a Martian (as opposed to a traveller), you will observe a day that takes as long as it takes on Mars for the sun to go through a rising-and-setting cycle. The rules-hack here is that one can consider that any place other than Earth is unnatural for humans, so any human, even if born on Mars, is "just visiting".

The above, I should note, is just me playing rules-lawyer, and emphatically not from any expertise in Jewish law.

[starmalachite.livejournal.com]

if you're on Mars, you're in Heaven.

Wow, who knew Ray Bradbuy was Jewish? Mars_is_Heaven!

[goljerp]

The above, I should note, is just me playing rules-lawyer, and emphatically not from any expertise in Jewish law

But that's the fun of Jewish law! It's all about the rules-lawyering!

How do you deal with observing shabbat when the local civil calendar has, let's say, 10 months, each consisting of six 9-local-day weeks of 17-local-hour days?

I think that since Humans have cicadian cycles approximating 24 earth hours (well, actually, I think it's closer to 25), we're not likely to see a human civilization set up something with local days which are more than a couple of hours away from 24.

But hours, weeks, and months are not hard-wired into people, and those could change. Actually, the "hours" that the Rabbis used in the Talmud are not equal to the hours we use today, so that change isn't a biggie. And months and weeks aren't a biggie, either -- right now it's May 2nd, according to the U.S. Calendar; that doesn't stop it from being 15 Iyar as well. (Hey, happy Pesach Sheini, everyone!) So it's really the length of a day which would be the problem for Jewish colonists.

Actually, I am making a big assumption: what if humans aren't so inflexible in their hard-wiring, and can adapt to 17 hour days? Well, then things get tricky again...

[goljerp]

I hate replying to myself, but re-reading your post, I realized that I totally ignored your point about weeks. That is a good point; if Shabbat is every 7 days, but a week on erehwon is 8 days, Shabbat would float... and that would be odd, indeed.

(maybe they would use 10 day weeks - the Metric calendar - that Garrison Keillor used to talk about: Oneday, Twoday, Tuesday, Wednesday, Mensday, Ladiesday, Thursday, Friday, Saturday, and Sunday. )

[geekosaur]

Er, weeks don't correspond to any natural time division; they're purely a man-made (or HaShem-made, depending on viewpoint) invention. Not even to lunar months (which are 29+ days, not 28). And the ancient Jews were more or less the only culture that kept anything like a week, much less Shabbat. (Babylonian kings occasionally declared "shappatu", but not on a regular schedule.)

IIRC the Rabbis of the Talmud understood this and specifically treated the week as an artificial time division instituted by HaShem specifically for Jews.

[zevabe.livejournal.com]

There is nothing that makes a week except Bereishit. A day is one rotation of your planet. A year is one revolution of your planet around its star. And a month is from one phase of the moon to the next iteration of that phase (which may be Earth-centric since other moons don't have to revolve and rotate at the same speed)*. But a week is, as far as I understand, not defined by a physical phenomenon but by human invention/convention. So seven days on mars is a week, just like 12 doughnuts on Mars is still a dozen. Also, aren't Martian days about as long as Earth days, so that isn't a big conversion over?

* Could someone explain to me what would happen in terms of phases of the moon(s) from the perspective of an observer standing on Mars? Would it look like phases of the moon here but just over some other period of time?

[geekosaur]

Actually, the phase of the moon has nothing to do with the moon's day vs. its orbital period; it's solely related to its angle relative to the Sun as seen from the Earth, so depends only on how long it takes the moon to orbit the Earth.

As seen from Mars, phases would behave rather differently, because they would be restricted by the Sun-Earth-Mars angles as well as the Sun-Moon-Earth angles. Also, the moon would usually be invisible: either behind the Earth, or in front of it and drowned out except when Earth and Mars are fairly close to each other (but then it would be a dark spot against a mostly dark spot, instead of a light spot against a very light spot).

[zevabe.livejournal.com]

I think I was insufficiently clear. If I stood on Mars, what would the phases of the moons of Mars look like? How long would a full cycle (new moon to new moon) take?

[geekosaur]

Wikipedia knows all....

[geekosaur]

At one point when I was having sleep issues, my "circadian" rhythm was running about 2 1/2 days; I suspect people could adapt to different physical days, up to a point (let's not think about Yom Kippur when the day is 36 hours, hm?).

[goljerp]

Hmm... I wonder how far the average person could adapt happily. Just because people could adapt to 36 hour days, would they want to? I seem to recall that you didn't seem too happy in your lj posts when you were on a 2.5 day cycle, but maybe that was just because you were trying to live in a world where everyone else was on a 24 hour cycle?

[geekosaur]

Yeh, the frustrating part was being out of synch with everything else. Hard to go shopping at 3am when there's nothing open nearby and no buses, for example.

[geekosaur]

My first impulse is to wonder if it's legitimate to consider that from a Biblical point of view, so to speak, if you're on Mars, you're in Heaven.

Actually, no; the planets, stars, etc. are part of raqi`a, not shamayim. At least according to the Sages, who reasoned that since the "heavenly bodies" are false idols/not "gods", they cannot possibly be in "the heavens", so must be in "the sky".

This is reflected in the ma`ariv prayer:

...u-m'sader et ha-kochavim b'mishm'roteihem ba-raqi`a ki-r'tzono...

...and Who orders the stars in their courses in the sky according to His will.

[cellio]

I suspect that hours in a day and days in a month would both be much more mutable than days in a week. The former two are based on astronomical events; the latter is biblical. The good news, though, is that humans are creatures of habit, so any colonies we establish are likely to have seven-day weeks.

Martian natives, on the other hand...

So, if you consider yourself to be a Martian (as opposed to a traveller), you will observe a day that takes as long as it takes on Mars for the sun to go through a rising-and-setting cycle.

I agree.

You know what's possibly strange? I suspect that the probability of humans on Mars just following Martian sun/moon is inversely proportional to the strength of the network connection to back home. You want to follow what seems natural, and that works so long as Chabad isn't sending you email every week saying "remember, Shabbat starts at 12:24 for you". :-)