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March 18, 2026<\/p>\n
3 min read<\/p>\n
Add Us On Google<\/span>Add SciAm<\/span><\/span><\/p>\n There might be less water on the moon than we\u2019d hoped<\/p>\n New satellite data come up dry as the search for lunar ice continues<\/p>\n By K. R. Callaway edited by Lee Billings<\/span><\/p>\n NASA’s ShadowCam photographed some of the moon’s darkest regions, including the permanently shaded regions at the bottom of craters.<\/p>\n JAXA\/NHK\/ZUMAPRESS.com\/Alamy<\/p>\n When Apollo 11 astronauts returned to Earth after accomplishing history\u2019s first-ever crewed moon landing, they brought back nearly 50 pounds of moon dust and rocks. Researchers who initially analyzed the material\u2019s parched composition came to an important (and flawed) conclusion: the moon was bone dry.<\/p>\n Undeterred, in all the decades since, some scientists kept up the search for lunar water, ultimately finding traces of it in samples returned by other moon missions. Hints of a potentially revolutionary breakthrough emerged in the 1990s, when a U.S. spacecraft, Clementine, spied tentative signs of water ice at the floors of craters called permanently shadowed regions (PSRs) around the lunar south pole. The case for water in lunar PSRs has grown across the years, but scientists are still struggling to pin down just how much might be there. Now a new study published today in Science Advances suggests the likely answer is \u201cnot much.\u201d<\/p>\n Analyzing images of the moon\u2019s darkest areas from ShadowCam, a NASA instrument on the Korea Pathfinder Lunar Orbiter, the study\u2019s authors determined that, in most of the moon\u2019s darkest craters, water makes up less than about 20 to 30 percent of the material by weight\u2014and that many may have no surface ice at all.<\/p>\n If you’re enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.<\/p>\n \u201cI think, based on what data we have now…, we are pretty sure there is ice on the surface,\u201d says Shuai Li, lead author of the study and a planetary geologist at the University of Hawaii at Manoa. The multibillion-dollar question remains just how abundant that ice is\u2014and thus how much future explorers might rely on it for producing potable water, manufacturing rocket fuel or merely studying its composition to better determine how it fits into the bigger picture of H2O\u2019s origins and evolution on the moon.<\/p>\n This latter matter has scarcely influenced competing Chinese and American efforts to build a moon base but could prove crucial for efforts to learn more about water\u2019s history throughout the entire solar system. The bulk of the moon\u2019s water was likely delivered via asteroid and comet impacts about four billion years ago, says David Kring, leader of the Center for Lunar Science & Exploration, who was not involved in the study. So tracking that water\u2019s abundance and distribution across the lunar surface could constrain the nature and number of the water-rich projectiles that are thought to have populated the inner solar system at that time.<\/p>\n Whatever water ice exists in lunar PSRs wasn\u2019t necessarily deposited there directly by infalling asteroids and comets; rather a process called \u201ccold trapping\u201d could have allowed ice to accumulate on dark, frigid crater floors on the moon via whiffs of impactor- or solar-wind-derived water vapor that wafted in from elsewhere. Similar processes are at play on other celestial bodies, such as Mercury and the dwarf planet Ceres. And for their new study, the researchers used preexisting measurements of water ice abundance within Mercury\u2019s PSRs to better calibrate their analysis of ShadowCam images of lunar PSRs.<\/p>\n Their result, the authors say, sets an upper limit on just how much water ice exists at the surface inside the moon\u2019s most shadowy craters. Ice signaled its presence via the scattering and reflectance of light, as seen by ShadowCam. Because the instrument, which has a detection limit of about 20 to 30 percent ice by weight, didn\u2019t pick up on these telltale signs in most PSRs, the research team is confident that most of these regions either lack ice or have lower concentrations of it\u2014at least on the surface. The results are somewhat ambiguous as to how much ice may lurk unseen beneath layers of overlying ice-sparse material.<\/p>\n So the search will continue. Li and his colleagues say the natural next step is to build and use better instruments that could identify even minuscule amounts of water ice in lunar soil. But others argue direct exploration of the treacherously dark and cold depths of lunar PSRs will offer the best chance of solving this mystery.<\/p>\n \u201cOrbital measurements like those that are reported in the current paper are fabulous in that they can provide broad regional surveys, but oftentimes what you\u2019re looking for can only be addressed by in situ, \u2018boots on the ground\u2019 exploration activities,\u201d Kring says. \u201cThe sooner that we get robotic and human assets on the lunar surface to investigate this particular issue, the sooner we\u2019ll have some definitive answers.\u201d<\/p>\n If you enjoyed this article, I\u2019d like to ask for your support. Scientific American<\/span> has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.<\/p>\n I\u2019ve been a Scientific American<\/span> subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm <\/span>always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.<\/p>\n If you subscribe to Scientific American<\/span>, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.<\/p>\n In return, you get essential news, captivating podcasts, brilliant infographics, can’t-miss newsletters, must-watch videos, challenging games, and the science world’s best writing and reporting. You can even gift someone a subscription.<\/p>\n There has never been a more important time for us to stand up and show why science matters. I hope you\u2019ll support us in that mission.<\/p>\n","protected":false},"excerpt":{"rendered":" March 18, 2026 3 min read Add Us On GoogleAdd SciAm There might be less water on the moon than we\u2019d hoped New satellite data come up dry as the search for lunar ice continues By K. R. Callaway edited by Lee Billings NASA’s ShadowCam photographed some of the moon’s darkest regions, including the permanently<\/p>\n","protected":false},"author":1,"featured_media":47060,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[50],"tags":[13600,1615,1183,4389],"class_list":{"0":"post-47059","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-environment","8":"tag-hoped","9":"tag-moon","10":"tag-water","11":"tag-wed"},"_links":{"self":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/posts\/47059","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=47059"}],"version-history":[{"count":0,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/posts\/47059\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/media\/47060"}],"wp:attachment":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=47059"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=47059"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=47059"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}On supporting science journalism<\/h2>\n
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