{"id":803799,"date":"2026-09-25T06:20:33","date_gmt":"2026-09-25T11:20:33","guid":{"rendered":"https:\/\/spaceweekly.com\/?p=803799"},"modified":"2026-09-25T06:20:33","modified_gmt":"2026-09-25T11:20:33","slug":"is-there-enough-water-on-the-moon-for-future-cities","status":"publish","type":"post","link":"https:\/\/spaceweekly.com\/?p=803799","title":{"rendered":"Is there enough water on the moon for future cities?"},"content":{"rendered":"


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Artist\u2019s concept of a future moon base. A new study suggests there would be enough water on the moon for smaller bases, villages or towns, but not larger cities. Image via ESA.<\/figcaption><\/figure>\n
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  • Is there enough water on the moon<\/strong> to support future large cities?<\/li>\n
  • There might not be enough water for larger cities<\/strong> of up to a million people, a new study suggests.<\/li>\n
  • But smaller towns or villages<\/strong> could survive for several centuries.<\/li>\n<\/ul>\n

    Science news, night sky events and beautiful photos,<\/strong> all in one place. Click here to subscribe to our free daily newsletter.<\/p>\n

    Enough water on the moon for cities?<\/h3>\n

    Scientists have found many deposits of water ice on the moon, particularly at its poles. But is there enough of it to sustain future humans living there in cities? <\/p>\n

    This is what Martin Elvis at the Center for Astrophysics | Harvard & Smithsonian in Cambridge, Massachusetts, questions in a new guest editorial article for Frontiers<\/em> on September 14, 2026.<\/p>\n

    Elvis and fellow astronomer Jonathan McDowelldid the math to try to answer this question. They found that lunar towns or even small cities might not run out of water for over 1,000 years \u2026 but moon cities of a million people would likely run out within a century.<\/p>\n

    The researchers published their peer-reviewed conclusions in Frontiers in Space Technologies<\/em> on September 13, 2026.<\/p>\n

    Ice at the moon\u2019s poles<\/h3>\n

    Scientists had long thought the moon to be completely dry. No water, not even ice. But in recent years, probes orbiting the moon have found evidence for ice at the moon\u2019s poles.<\/p>\n

    The ice is hiding in extremely frigid \u201ccold traps,\u201d which are deeply-shadowed craters that never see sunlight. This ice has not seen direct sunlight for about 4 billion years. And that ice doesn\u2019t sublimate away (turn from solid to gas) more than a millimeter every billion years.<\/p>\n

    There might be as much as a billion tons of ice in these dark craters, although estimates vary. So that sounds like good news, right? Well, maybe \u2026 maybe not.<\/p>\n

    Is a city on the moon sustainable?<\/h3>\n

    The researchers started by asking the question:<\/p>\n

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    How sustainable is a city on the moon?<\/p>\n<\/blockquote>\n

    It turned out that power isn\u2019t an issue. While the depths of the craters are always in darkness, the rims of the craters do see sunlight. The researchers found that it would be possible to generate three gigawatts of electricity using kilometer-tall towers covered with solar panels.<\/p>\n

    \"Water
    View larger. | This map shows the distribution of permanently shadowed regions (PSRs), in blue, around the lunar south pole. The PSRs reach up to about 80 degrees south latitude. The elevation map is from Lunar Orbiter Laser Altimeter instrument on NASA\u2019s Lunar Reconnaissance Orbiter (LRO) spacecraft. It\u2019s in these regions that evidence of water ice has been found. Image via NASA\/ GSFC\/ Timothy P. McClanahan.<\/figcaption><\/figure>\n

    .<\/p>\n

    Not enough water on the moon<\/h3>\n

    It\u2019s the need for water that brings problems.<\/p>\n

    The study\u2019s calculations showed that even if there was a billion tons of water locked up as ice, a large city of up to a million people might last only decades. Such a large permanent settlement would need water for drinking, hygiene, food production and life-support systems. And this is the crux of it all: the water is a finite resource<\/em>.<\/p>\n

    And if the residents achieved 98% water recycling, as the paper postulates, the city would still run out of water in just over a century. That kind of water recycling has already been achieved on the International Space Station (ISS).<\/p>\n

    The paper states:<\/p>\n

    \n

    Permanently Shadowed Regions near the lunar poles are insufficient to support a population of one million using ISS-level (98%) recycling for more than about one century. Unless recycling can be improved by factors of about 10, or a similarly greater water supply is discovered, this result precludes large-scale long-term human habitation of the moon.<\/p>\n<\/blockquote>\n

    Note that this figure of a century is an estimate from two researchers, not an established barrier.<\/p>\n

    The paper\u2019s estimates are based on a model of 1 million people at 500 tons of water\/person\/year of total water demand, with 98% recycling. That\u2019s reasonable, but again doesn\u2019t come from a standard scientific consensus.<\/p>\n

    \"Shadowy
    View larger. | An example of a Permanently Shadowed Region. At the moon\u2019s poles and with the sun at such a low angle, sunlight never reaches the floors of some deep craters. These permanently shadowed regions are some of the coldest spots in the solar system, trapping volatile chemicals including water ice. Image via NASA\u2019s Scientific Visualization Studio\/ SwRI.<\/figcaption><\/figure>\n

    Less water than previously thought<\/h3>\n

    There\u2019s still this one basic and important problem: we still don\u2019t know exactly<\/em> how much water there is on the moon. There is still a lot of uncertainty of the amount of water ice. And current remote sensing from orbit doesn\u2019t adequately probe the deeper regolith. We need better surveys, reaching deeper underground, where some scientists think there is a good chance of finding more ice.<\/p>\n

    A study from earlier this year suggested there is much less water ice at the moon\u2019s poles than previously thought. The study we\u2019re discussing in this article used the figure of a billion tons, but other current estimates of the amount of water say it is likely about 30 times less<\/em> than that. Another study from 2022 estimated only 34 million tons. <\/p>\n

    If so, a city of a million people might actually only have enough water for decades, rather than a century. <\/p>\n

    That said, a city of a million people on the moon seems like an extreme possibility. It will still be several years before Artemis astronauts can begin to establish a base camp on the moon. Maybe with a few buildings, but barely large enough to even be considered a village. Water running out would not be a concern for such a settlement. <\/p>\n

    In fact, the study notes that even a settlement of 100,000 people would have enough water for 1,000 years (with ISS-level recycling efficiency).<\/p>\n

    Any larger cities \u2014 if they ever happen \u2014 are likely hundreds of years away. And by that time, we should have a much better idea of exactly how much water there really is on the moon, and better water recycling abilities.<\/p>\n

    \"Bald
    Martin Elvis at the Harvard Smithsonian Center for Astrophysics is one of the two authors of the new study about water on the moon. Image via Harvard Smithsonian Center for Astrophysics.<\/figcaption><\/figure>\n

    .<\/p>\n

    \"Man
    Jonathan McDowell, formerly at the Center for Astrophysics | Harvard & Smithsonian until this year, is one of two authors of the new study about water on the moon. Image via Jonathan McDowell.<\/figcaption><\/figure>\n

    Possible solutions<\/h3>\n

    So obviously, the smaller the better for being sustainable. Thinking far <\/em>into the future \u2026 is there any way a much larger city could survive? There are some suggested solutions.<\/p>\n