{ "slug": "asteroid-impact-death", "question": "What are the odds of dying from an asteroid or comet impact?", "category": "natural", "no_reliable_estimate": false, "perceived": { "description": "Asteroid impacts occupy a peculiar slot in the public imagination: simultaneously dismissed as science fiction and cited as an existential threat. No rigorous population survey tracks how often Americans worry about asteroid strikes specifically, but asteroid-impact scenarios reliably generate outsized media coverage whenever a newly discovered near-Earth object makes a close approach. The result is an availability-driven sense that the risk is either zero or catastrophic, with little middle ground.\n", "rough_estimate": "~1 in 10,000 lifetime feels plausible to many who recall the dinosaur analogy", "kind": "intuition" }, "native": { "display": "~100 expected fatalities per year globally (statistical average)", "numerator": 100, "denominator": 8000000000, "unit": "per year", "population": "Global population, all ages, statistical expectation over geological timescales" }, "normalized": { "lifetime_us_adult": 7.4e-7, "display": "~1 in 1,350,000 lifetime (US adult)", "log_value": -6.13, "assumptions": "Post-Spaceguard estimates put the annualized expected fatalities from asteroid and comet impacts at roughly 100 per year globally, down from the ~1,000/yr figure Chapman & Morrison used in 1994, because the survey has retired the statistical contribution of most civilization-ending impactors (≥1 km). Annual individual risk: 100 / 8 × 10⁹ ≈ 1.25 × 10⁻⁸. Compounded over 59 remaining adult years: 1 − (1 − 1.25 × 10⁻⁸)⁵⁹ ≈ 7.4 × 10⁻⁷. This is a statistical expectation smoothed over millions of years; in any given century the probability of a fatal impact is dominated by a single low-probability, high-casualty event.\n", "uncertainty": { "low": 1e-7, "high": 0.000006 }, "scope": "global_adult_lifetime" }, "sources": [ { "url": "https://www.nature.com/articles/367033a0", "title": "Impacts on the Earth by asteroids and comets: assessing the hazard", "publisher": "Nature", "source_type": "peer_reviewed", "statistic": "Individual lifetime risk of ~1 in 6,000 over 50 years (pre-Spaceguard, including civilization-ending impacts)", "excerpt": "\"There is a 1-in-10,000 chance that a large (~2-km diameter) asteroid or comet will collide with the Earth during the next century, disrupting the ecosphere and killing a large fraction of the world's population.\"\n", "source_date": "1994-01-06", "source_accessed": "2026-04-12", "archive_url": "http://web.archive.org/web/20260129114720/https://www.nature.com/articles/367033a0", "calculation_notes": "Chapman & Morrison 1994 estimated ~1,000 expected fatalities per year globally from all NEO sizes, yielding a 50-year individual risk of roughly 1 in 6,000. This was a pre-Spaceguard estimate that included the full statistical contribution of rare civilization-ending impacts (≥1 km). Subsequent survey work has retired most of that contribution; the revised post-Spaceguard expectation is ~100 fatalities/yr, which reduces the lifetime figure by roughly an order of magnitude.\n", "independence_note": "Chapman & Morrison's framework is the foundational risk assessment; later estimates by Stokes et al. (2003) and Rumpf et al. (2017) use independent impact-physics models and updated NEO population surveys but build on the same probabilistic approach.\n" }, { "url": "https://cneos.jpl.nasa.gov/sentry/", "title": "Sentry: Earth Impact Monitoring", "publisher": "NASA Center for Near Earth Object Studies", "source_type": "govt_report", "statistic": "No known large NEO has any significant probability of impacting Earth in the next 100 years; 95%+ of 1 km+ NEOs catalogued", "excerpt": "\"Sentry is a highly automated collision monitoring system that continually scans the most current asteroid catalog for possibilities of future impact with Earth over the next 100 years.\"\n", "source_date": "2025-12-31", "source_accessed": "2026-04-12", "archive_url": "http://web.archive.org/web/20260318035242/https://cneos.jpl.nasa.gov/sentry/", "calculation_notes": "NASA CNEOS Sentry continuously monitors all catalogued NEOs. As of 2025, approximately 95% of near-Earth asteroids 1 km and larger have been discovered, and none has a significant impact probability in the next century. The residual risk comes almost entirely from undiscovered objects below 140 m. The post-survey annualized fatality expectation of ~100/yr globally (down from ~1,000/yr) reflects this retired risk. Individual annual risk: 100 / 8 × 10⁹ ≈ 1.25 × 10⁻⁸. Over 59 adult years: 1 − (1 − 1.25 × 10⁻⁸)⁵⁹ ≈ 7.4 × 10⁻⁷ ≈ 1 in 1,350,000.\n", "independence_note": "CNEOS Sentry is an operational monitoring system tracking real NEOs with radar and optical astrometry. Its data are independent of the statistical population models used by Chapman & Morrison and Rumpf et al.\n" }, { "url": "https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2017GL073191", "title": "Asteroid impact effects and their immediate hazards for human populations", "publisher": "Geophysical Research Letters", "source_type": "peer_reviewed", "statistic": "Wind blast and overpressure are the dominant casualty mechanisms for land impacts of 50–400 m asteroids", "excerpt": "\"We find that wind blast is the most dangerous impact effect, followed by pressure shock wave and thermal radiation. These three effects account for the vast majority of casualties.\"\n", "source_date": "2017-04-19", "source_accessed": "2026-04-12", "archive_url": "http://web.archive.org/web/20250702150434/https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2017GL073191", "calculation_notes": "Rumpf et al. 2017 extended casualty modeling to smaller impactor sizes than Chapman & Morrison considered, using high-fidelity impact-physics simulations. Their per-impactor casualty estimates are broadly consistent with earlier work but refine the hazard allocation across effects. The headline lifetime probability we use derives from the post-Spaceguard annualized expectation (~100 fatalities/yr) rather than from Rumpf's per-event figures directly, but Rumpf's work validates the casualty-per-impact assumptions underlying that expectation.\n", "independence_note": "Rumpf et al. use independent impact-physics and population-exposure models distinct from both Chapman & Morrison's analytical approach and CNEOS's orbit-monitoring system.\n" } ], "comparison_anchors": [ { "label": "Death by lightning strike (lifetime, US)", "lifetime_us_adult": 0.00000354 }, { "label": "Death by shark attack (lifetime, US)", "lifetime_us_adult": 1e-7 }, { "label": "Dying in a plane crash (lifetime, US adult, ~2 flights/yr)", "lifetime_us_adult": 0.000017 } ], "short_label": "Asteroid impact", "myth_framing": "overrated", "outcome_severity": "fatal", "exposure_pattern": "acute", "outcome_type": "existential", "valence": "negative", "caveats": "The \"lifetime probability\" of dying from an asteroid impact is a statistical fiction in a way that most other entries on this site are not. Almost all the expected fatalities come from a single class of event — a large (≥140 m) impactor striking a populated area or triggering a global catastrophe — that has not occurred in recorded history. The annualized figure of ~100 expected fatalities per year is the quotient of billions of potential casualties divided by millions of years between events. In any given human lifetime, the actual probability is overwhelmingly either zero (no impact occurs) or catastrophically high (one does). The uncertainty band spans more than an order of magnitude because the residual population of undiscovered sub-140 m objects is poorly constrained, and because casualty estimates for ocean impacts (tsunami generation) vary by factors of 10–100 depending on modeling assumptions.\n", "quality_score": { "d1": 5, "d2": 5, "d3": 5, "d4": 5, "d5": 5, "d6": 5, "d7": 3, "d8": 5, "avg": 4.75, "scored_by": "claude-code-8d", "scored_at": "2026-05-25", "methodology_version": "1.2" }, "reviewer": "likelier-gate-review", "last_reviewed": "2026-04-16", "reviewed": true, "generated_at": "2026-04-12", "image": { "alt": "A single stylized asteroid silhouette against a dark sky with faint star-field dots, flat vector illustration." }, "attribution": "Likelier — https://likelier.app", "license": "https://creativecommons.org/licenses/by-sa/4.0/", "support": "https://buymeacoffee.com/kgluszczyk?via=likelier&utm_content=api-fear-single", "canonical_url": "https://likelier.app/asteroid-impact-death" }