I don't really know from where in the Torah or from which Rabbi this comes from, but I've heard that the Torah prohibits leaving the planet. Maybe it is because every mitzvah is made for Earth only, or because the Mitzvot that rely on time (like Shabbat and Tefilot) can't be done outside the planet.

Is this a real prohibition? Is there anything in judaism that actually discusses this?

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    Well, we have a bunch of questions that discuss halachot in outer-space, so it seems that at least some rabbis permit it.
    – Scimonster
    Nov 1, 2015 at 10:20
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    @DannySchoemann …jumping?
    – msh210
    Nov 1, 2015 at 14:09
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    @Gabe12 not the rebbi I'm quoting. He commented that the ozone hole began after the first manned space flight as a punishment.
    – rosends
    Nov 1, 2015 at 15:23
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    @Scimonster There are halachot about what to do after (e.g.) missing davening. That doesn't mean that it's ok to miss davening.
    – Daniel
    Nov 1, 2015 at 15:24

5 Answers 5


R' Menachem Kasher, in האדם על הירח, proposes that ומלאו את הארץ וכבשוה, "fill the land and conquer it," may be an inference to prohibit space travel. He also points to the danger involved.


Rav Aviner was asked how there would be room on Earth after the resurrection. His answer was that, according to Rav Kook, we would live on other planets.

The source seems to be in Rav Kook's Linvuchei Hador:

"כי ברב ההשתלמות ההדרגתית יתגלו עוד בנקל דרכים להתיישב בכוכבים רבים ובעולמות אין מספר."

So no.

  • Where are these words in לנבוכי הדור? The entire text is available on Sefaria.org
    – Chaim
    May 17, 2017 at 14:14
  • Right, thanks. I added the link to the source. Rav Kook is talking about something slightly different than the way Rav Aviner is.
    – Josh
    May 17, 2017 at 14:20
  • Maybe that's only after the Resurrection, when it's an oneis, but until then it would be forbidden?
    – DonielF
    Feb 21, 2019 at 19:00
  • You meant to say that R' Kook didn't prohibit it, knowing it's possible.
    – Al Berko
    Nov 19, 2019 at 19:51

Even according to those that allow it, (assuming there are those who prohibit space travel,) the halachos of zmanei tefilah, shabbos and all zman related halachos get very complicated. So I assume also they would strongly discourage space travel, whereas flying on a plane doesn't nearly have the same issues (usually at most one or two tefilos). For the same reason it is discouraged to fly past the date line during sefirah, as it complicates when shavuos is.

  • How does it answer the question? But it's good as a comment.
    – Al Berko
    Nov 19, 2019 at 19:50

Although I haven't heard the shiur in a while, I believe Rav Moshe Heinemann said his Rosh Yeshiva Rav Aharon Kotler ztl mentioned it May be an issue of going to the moon based on the understanding that the dor haflaga was trying to make a space ship; also shamayim L'Hashem v'haaretz nasan lvbei Adam - the Heavens are for Hashem while humans are on earth.


I didn't know if you asked about the Torah or about our contemporary Rabbis, because space travel was considered theoretically impossible up until the middle of the 20th century!

  1. The Torah says that G-d created the firmament to divide between the waters, and the firmament - firm it is (Gen 1.14).

  2. In the story of the Babel Tower (Gen 11.5) the Midrash says they wanted to drill it and let the upper water drain.

  3. The Torah emphasizes numerous times pretty literally that:

    The heavens are the Lord’s and the earth He has given over to mankind” (Psalms 115:16).

  4. Regarding our Rabbis' reaction please see "how-did-gdoley-israel-react-to-the-landing-on-the-moon"

  • Although Rambam felt that we could not reach the moon, it is inaccurate to suggest all rabbis or even the Torah, for that matter felt the same way. For one, Ralbag knew the sun was the center, and the Bible never meant for its words to be taken literally. See Philo.
    – Turk Hill
    Nov 19, 2019 at 19:17
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    @TurkHill Yeas we all are very smart retrospectively. Many love Judaism for our ability to pick and choose - first we burn Rambam's books and then we claim we always counted on him. I think we should be strong enough to admit our heritage as it is. One hint is not enough to present it as the official Jewish standpoint.
    – Al Berko
    Nov 19, 2019 at 19:28
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    God wrote the Torah, and God knew that space travel was possible.
    – Heshy
    Nov 19, 2019 at 19:29
  • @AlBerko I agree with you. Actually, I need to correct my statement, because I remember Rabbi Dr. Natan Slifkin saying that most Jews rejected copernicus theory at first.
    – Turk Hill
    Nov 19, 2019 at 19:35
  • @Heshy This may come as a shock for most laypeople, but the Torah is a great human achievement but nevertheless, only a human achievement. For what exactly is “revelation”? Maimonides writes in the first chapter of his Mishneh Torah that G-d does not speak. How was the Torah revealed?
    – Turk Hill
    Nov 19, 2019 at 19:36

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