{"id":74074,"date":"2025-08-11T06:52:10","date_gmt":"2025-08-11T06:52:10","guid":{"rendered":"https:\/\/www.newsbeep.com\/us\/74074\/"},"modified":"2025-08-11T06:52:10","modified_gmt":"2025-08-11T06:52:10","slug":"metallic-beads-suggest-a-comet-slammed-into-earth-not-long-ago","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/us\/74074\/","title":{"rendered":"Metallic beads suggest a comet slammed into Earth not long ago"},"content":{"rendered":"<p>Tiny metallic beads hiding in deep Arctic mud have reignited a long-running argument about why Earth shivered 12,800 years ago. The new <a href=\"https:\/\/journals.plos.org\/plosone\/article?id=10.1371\/journal.pone.0328347\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">evidence<\/a> comes from four sediment cores lifted out of Baffin Bay, between Greenland and Canada, that capture a razor-thin layer rich in comet-like debris.<\/p>\n<p>The abrupt climate lurch, known as the <a href=\"https:\/\/www.ncei.noaa.gov\/sites\/default\/files\/2021-11\/3%20The%20Younger%20Dryas%20-FINAL%20NOV%20%281%29.pdf\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">Younger Dryas<\/a>, drove Northern Hemisphere temperatures down roughly 18\u00b0F in what ice cores suggest was a matter of months. <\/p>\n<p><a href=\"https:\/\/earthsnap.onelink.me\/3u5Q\/ags2loc4\" rel=\"noopener nofollow\" target=\"_blank\">&#13;<br \/>\n    <img decoding=\"async\" class=\"fit-picture\" loading=\"lazy\" src=\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2025\/07\/1753650490_38_earthsnap-banner-news.webp.webp\" alt=\"EarthSnap\"\/>&#13;<br \/>\n<\/a><\/p>\n<p><a href=\"https:\/\/sc.edu\/study\/colleges_schools\/artsandsciences\/sc_institute_archeology_and_anthropology\/faculty-staff\/moore_christopher.php\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">Dr. Christopher Moore<\/a> of the University of South Carolina (<a href=\"https:\/\/sc.edu\/\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">SC<\/a>) says his team\u2019s ocean-core data link that chill to incoming space dust rather than to a pulse of glacial meltwater.<\/p>\n<p>Comet or meltwater cause of ice age<\/p>\n<p>Most textbooks trace the cold spell to floods from the collapsing Laurentide Ice Sheet that diluted Atlantic surface water and slowed heat-bearing currents. <\/p>\n<p>The rival impact idea argues that Earth blundered into a comet stream, causing airbursts, fires, and a short impact winter that tipped the climate until ocean circulation recovered.<\/p>\n<p>That second scenario burst onto the scene in 2007 when scientists <a href=\"https:\/\/www.pnas.org\/doi\/10.1073\/pnas.0706977104\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">reported<\/a> soot, glassy spheres, and a sharp platinum spike at dozens of continental sites. <\/p>\n<p>Skeptics soon countered that those clues could be contamination or the by-products of ordinary surface processes, and many paleoclimatologists stayed loyal to the meltwater narrative.<\/p>\n<p>Deep cores show comet debris in Ice Age<\/p>\n<p>Moore\u2019s group hunted for evidence beyond the reach of plows, factories, and foot traffic. <\/p>\n<p>They sampled cores resting up to 1.5 miles beneath the waves and more than 20 feet below the modern seabed, then dated each layer with foraminifera radiocarbon counts.<\/p>\n<p>At the Younger Dryas boundary the cores show dense clusters of iron-rich glassy balls called <a href=\"https:\/\/www.hou.usra.edu\/meetings\/metsoc2023\/pdf\/6214.pdf\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">microspherules<\/a> and nickel-bearing splinters known as metallic dust particles, both typical of flash-melt events. <\/p>\n<p>They also register peaks in platinum group elements, notably platinum and iridium, whose cosmic abundance dwarfs crustal levels.<\/p>\n<p>\u201cOur identification of a Younger Dryas impact layer in deep marine sediments underscores the potential of oceanic records to broaden our understanding of this event and its climatological impacts,\u201d said Dr. Moore.\u00a0<\/p>\n<p>Mix of earth and comet dust in Ice Age<\/p>\n<p>The team compared element ratios in the spheres with stardust scooped from <a href=\"https:\/\/science.nasa.gov\/solar-system\/comets\/81p-wild\/\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">Comet Wild 2<\/a> and with cosmic dust caught in the upper atmosphere. <\/p>\n<p>Most spheres carried a terrestrial silicon-iron signature seasoned with about one percent extraterrestrial nickel and chromium, the blend expected when searing shock fronts melt local rock while sprinkling comet grains.<\/p>\n<p>Every year Earth sweeps up roughly 5,000 tons of <a href=\"https:\/\/agupubs.onlinelibrary.wiley.com\/doi\/full\/10.1002\/2017JD027143\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">space dust<\/a>, hardly enough to leave a global platinum spike, let alone trigger a centuries-long chill. <\/p>\n<p>By contrast, the Baffin Bay layer implies a six-month influx of millions of tons, three orders of magnitude above the background drizzle.<\/p>\n<p>Comet theory vs meltwater theory<\/p>\n<p>Freshwater <a href=\"https:\/\/www.science.org\/doi\/10.1126\/sciadv.aay2915\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">models<\/a> can still reproduce the cold if enough melt pours into the North Atlantic at once. A separate <a href=\"https:\/\/www.nature.com\/articles\/s43247-021-00228-1\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">study<\/a> even showed that floods routed through the Hudson Valley could jolt Atlantic circulation without outside help.<\/p>\n<p><a href=\"https:\/\/www.pnas.org\/doi\/10.1073\/pnas.1313495110\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">Critiques<\/a> of the impact work also persist, noting mismatched dates at some sites and the absence of an obvious crater. <\/p>\n<p><a href=\"https:\/\/cff2.earth.com\/uploads\/2025\/08\/09095058\/metallic-beads_young-dryas_comet-impact_ice-age_credit-PLOS-One_1m.jpg\" rel=\"nofollow noopener\" target=\"_blank\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"300\" src=\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2025\/08\/metallic-beads_young-dryas_comet-impact_ice-age_credit-PLOS-One_1s.webp.webp\" alt=\"Examples of Fe-rich and silica-rich impact microspherules (a and b) and metallic dust particles (MDPs; c and d) interpreted as cometary dust from Baffin Bay cores. Yellow arrows show particles of FeSi, FeS, and FeCr on microspherules (a and b) and NiFe, low-O2 Fe, and native Fe on metallic particles (c and d). Note folded edges of MDP in panel d. Credit: Moore et al., 2025, PLOS One, CC-BY 4.0\" class=\"wp-image-1980987\"  \/><\/a>Examples of Fe-rich and silica-rich impact microspherules (a and b) and metallic dust particles (MDPs; c and d) interpreted as cometary dust from Baffin Bay cores. Yellow arrows show particles of FeSi, FeS, and FeCr on microspherules (a and b) and NiFe, low-O2 Fe, and native Fe on metallic particles (c and d). Note folded edges of MDP in panel d. Click image to enlarge. Credit: Moore et al., 2025, PLOS One, CC-BY 4.0<\/p>\n<p>Moore replies that low-altitude airbursts leave little more than tiny glassy fallout, and that glacial erosion would quickly erase shallow craters on an ice sheet.<\/p>\n<p>Comet strike effects on life<\/p>\n<p>Beyond the immediate cooling, an extraterrestrial strike of this scale could have set off a chain of environmental disruptions. <\/p>\n<p>Soot from widespread wildfires, combined with fine cometary dust, may have dimmed sunlight long enough to stress plant life and ripple through food webs.\u00a0<\/p>\n<p>Layers from the <a href=\"https:\/\/www.earth.com\/news\/ice-age-climate-shifts-changed-early-human-migration-patterns\/\" rel=\"nofollow noopener\" target=\"_blank\">Younger Dryas<\/a> period in several regions hold signs of intense biomass burning, adding weight to the idea of global ecological shock.<\/p>\n<p>Large-scale die-offs of megafauna and abrupt changes in human settlement patterns appear in archaeological records from this period. <\/p>\n<p>While correlation does not prove causation, the overlap in timing between these biological shifts and the impact proxies in the sediment has kept the hypothesis alive in both paleontology and anthropology circles.<\/p>\n<p>Ice Age comet event climate lessons<\/p>\n<p>Understanding how fast the climate can flip is not just academic. If a brief dust veil could stall <a href=\"https:\/\/www.earth.com\/news\/cold-spot-in-the-atlantic-could-signal-big-trouble-for-global-climate\/\" rel=\"nofollow noopener\" target=\"_blank\">Atlantic circulation<\/a> once, large volcanic plumes or human-caused soot might hold similar leverage.<\/p>\n<p>The work also widens the hunt for ancient impacts to offshore archives, where mud builds quietly and contamination risks drop. <\/p>\n<p>Future cores from the North Atlantic, Arctic Ocean, and even the Gulf of Mexico could trace the fallout plume and settle how widely the particles spread.<\/p>\n<p>For now the Baffin Bay cores add a fresh puzzle piece rather than the final picture. Whether that piece fits better with a cosmic hailstorm or with rampaging meltwater remains an open, and lively, question.<\/p>\n<p>The study is published in <a href=\"https:\/\/journals.plos.org\/plosone\/article?id=10.1371\/journal.pone.0328347\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">PLOS One<\/a>.<\/p>\n<p>\u2014\u2013<\/p>\n<p>Like what you read? <a href=\"https:\/\/www.earth.com\/subscribe\/\" rel=\"nofollow noopener\" target=\"_blank\">Subscribe to our newsletter<\/a> for engaging articles, exclusive content, and the latest updates.\u00a0<\/p>\n<p>Check us out on <a href=\"https:\/\/www.earth.com\/earthsnap\/\" rel=\"nofollow noopener\" target=\"_blank\">EarthSnap<\/a>, a free app brought to you by <a href=\"https:\/\/www.earth.com\/author\/eralls\/\" rel=\"nofollow noopener\" target=\"_blank\">Eric Ralls<\/a> and Earth.com.<\/p>\n<p>\u2014\u2013<\/p>\n","protected":false},"excerpt":{"rendered":"Tiny metallic beads hiding in deep Arctic mud have reignited a long-running argument about why Earth shivered 12,800&hellip;\n","protected":false},"author":2,"featured_media":74075,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[48],"tags":[79,193],"class_list":["post-74074","post","type-post","status-publish","format-standard","has-post-thumbnail","category-space","tag-science","tag-space"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/74074","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/comments?post=74074"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/74074\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media\/74075"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media?parent=74074"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/categories?post=74074"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/tags?post=74074"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}