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Discovered in spacecraft cleanrooms, the fungus survived multiple stressors designed to simulate Mars, highlighting a potential gap in how missions protect other worlds from contamination.<\/p>\n
Survivor in cleanrooms<\/p>\n
Inside spacecraft assembly cleanrooms, researchers found fungal strains that had already endured the cleaning meant to remove Earth microbes<\/a> from Mars-bound hardware.<\/p>\n Dr. Kasthuri Venkateswaran documented Aspergillus calidoustus as the strain that kept making it through the harshest stages.<\/p>\n At NASA\u2019s Jet Propulsion Laboratory (JPL<\/a>), Venkateswaran\u2019s team followed the fungus from cleaning heat through space radiation to Martian stress.<\/p>\n That boundary turns the finding into a risk problem for mission planners, not a claim that Mars is already threatened.<\/p>\n Built for extreme survival<\/p>\n Among 27 fungal strains from Mars 2020 rover assembly areas, 23 survived an early blast of germ-killing light before deeper testing.<\/p>\n Under that light, those spores showed unusual tolerance to ultraviolet radiation<\/a> \u2013 high-energy sunlight that can damage cells on exposed surfaces.<\/p>\n Those conidia, dry reproductive spores that help fungi spread, allowed the fungus to stay inactive through heat, cold, and radiation for long periods.<\/p>\n \u201cMicroorganisms can possess extraordinary resilience to environmental stresses,\u201d said Venkateswaran.<\/p>\n Mars makes fungus survival harder<\/p>\n Mars is a harsh place to survive. Its thin carbon dioxide atmosphere does little to block intense sunlight, leaving the dry surface exposed to damaging radiation during the day.<\/p>\n Even so, in lab tests, Aspergillus calidoustus managed to survive 24 hours of simulated Martian sunlight on spacecraft-grade metal \u2013 though its numbers dropped sharply, by about 1,000-fold.<\/p>\n Adding a layer of regolith \u2013 the loose rock and dust that covers Mars<\/a> \u2013 sometimes reduced the damage, but not in any consistent way. It offered some shielding, but not enough to reliably protect the spores.<\/p>\n What finally stopped the fungus was not a single condition but several hitting at once \u2013 a critical point, because on Mars, stresses rarely act alone.<\/p>\n Cold makes the difference<\/p>\n Temperature turned out to be a key part of the story. When samples were cooled to -76\u00b0F and exposed to radiation at the same time, the outcome shifted.<\/p>\n Under those combined conditions \u2013 cold air and harsh sunlight \u2013 the fungus could no longer grow. Its cell surfaces became damaged and scarred, leaving far fewer surviving spores behind.<\/p>\n But cold by itself was not enough to wipe it out. When sunlight was removed from the equation, some spores still held on.<\/p>\n That pattern points to a bigger takeaway. Survival depended on combinations of stress, not just one factor, suggesting that standard cleaning tests may miss how space conditions actually stack up during a real mission.<\/p>\n Radiation leaves lasting damage<\/p>\n During spaceflight testing, the conidia faced ionizing radiation<\/a>, particle energy strong enough to break chemical bonds over long periods.<\/p>\n After one month, living spores fell by 35 percent, and after six months they fell by 57 percent compared with unexposed samples.<\/p>\n Months of low-level radiation look different from one harsh blast, because damage accumulates slowly over time.<\/p>\n Such endurance matters for Mars missions, where a hidden survivor would spend months inside hardware before landing on another world.<\/p>\n Heat leaves survivors<\/p>\n Before launch, some spacecraft parts undergo dry-heat microbial reduction, baking hardware to cut living contamination without chemicals.<\/p>\n At 257\u00b0F, Aspergillus calidoustus outlasted another fungus and matched a tough bacterial spore during early heat exposure<\/a>.<\/p>\n Raising the heat to 302\u00b0F killed all three tested organisms after only five minutes in the same setup.<\/p>\n By surviving lower heat, the fungus challenged cleaning habits that measure success mainly against bacterial spores on mission hardware.<\/p>\n Expanding contamination safeguards<\/p>\n For NASA, planetary protection, rules that limit biological contamination between worlds, protects exploration from false clues while preserving the science.<\/p>\n Standard screens still lean heavily on bacterial spores, so fungal bioburden, the living microbes on equipment, may slip through between checks.<\/p>\n \u201cThis does not mean contamination of Mars is likely, but it helps us better quantify potential microbial survival risks,\u201d said Venkateswaran.<\/p>\n Engineers call that forward contamination<\/a>, Earth microbes carried to another world like Mars, and this fungus narrows the margin for error.<\/p>\n Fungi pose wider threats<\/p>\n Beyond spaceflight, hardy fungal spores can trouble industries that rely on heat, radiation, or spotless rooms far beyond launch pads.<\/p>\n Outside spacecraft, the Centers for Disease Control and Prevention (CDC<\/a>), lists this fungal group as a lung infection risk for people with weakened immunity.<\/p>\n Food and drug makers also fight fungal survival, because spores can persist when ordinary cleaning looks successful across production lines.<\/p>\n Clearer fungal testing could improve spacecraft safety while giving other sterile industries better warning signs before a costly failure.<\/p>\n Survival doesn\u2019t mean success<\/p>\n Even with these findings, important limits remain. No experiment showed that this fungus could actually grow, spread, or reproduce on Mars under the same conditions.<\/p>\n Survival, in this case, only means that some spores stayed alive after harsh treatment. It does not mean Mars would become habitable or welcoming to Earth life.<\/p>\n Real Martian conditions could be far more complex. Salts, shifting dust, long periods of darkness, and chemical stresses may interact in ways the lab tests did not fully capture.<\/p>\n That gap points to what comes next. Future experiments need to follow fungi across full mission timelines, tracking what happens not just after cleaning or landing, but throughout the journey.<\/p>\n For spacecraft<\/a> teams, the takeaway is clear. Cleaning protocols now have a sharper target \u2013 fungi that can survive individual stresses but may fail when multiple hazards combine.<\/p>\n That insight could help refine heat treatments, expand monitoring, and better protect the search for life on Mars before missions ever leave Earth.<\/p>\n The study is published in the journal Applied and Environmental Microbiology<\/a>.<\/p>\n \u2014\u2013<\/p>\n Like what you read?\u00a0Subscribe to our newsletter<\/a>\u00a0for engaging articles, exclusive content, and the latest updates.<\/p>\n Check us out on\u00a0EarthSnap<\/a>, a free app brought to you by\u00a0Eric Ralls<\/a>\u00a0and Earth.com.<\/p>\n \u2014\u2013<\/p>\n","protected":false},"excerpt":{"rendered":"Keeping Mars free from Earth life is one of the most important rules in space exploration. If microbes…\n","protected":false},"author":2,"featured_media":624152,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[64,63,128],"class_list":{"0":"post-624151","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-science","8":"tag-au","9":"tag-australia","10":"tag-science"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/624151","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/comments?post=624151"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/624151\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media\/624152"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media?parent=624151"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/categories?post=624151"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/tags?post=624151"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}