People have witnessed supernovae for millennia, but what threat do they pose to life on Earth? This video is sponsored by Brilliant. You can get started for free, or the first 200 people to sign up via https://brilliant.org/veritasium get 20% off a yearly subscription. ▀▀▀ A massive thanks to Prof. Hans-Thomas Janka for helping us with the physics of supernovae and GRBs. A massive thanks to Prof. Brian Thomas for all of his help with the terrestrial effects of supernovae and GRBs. This video would not have been possible without them. Also thanks to Dr. Luke Barnes for his initial help with the literature search. Hydrogen bomb vs Supernova fact was taken from this great article by xkcd/Randall Munroe – https://what-if.xkcd.com/73/ (based on the calculation by Andrew Karam, 2002) Cosmic bubble footage from https://www.cfa.harvard.edu/news/1000-light-year-wide-bubble-surrounding-earth-source-all-nearby-young-stars Neutrino driven SN explosion simulations from https://iopscience.iop.org/article/10.1088/2041-8205/808/2/L42 ▀▀▀ References: Melott, A. et al. (2019). Hypothesis: Muon radiation dose and marine megafaunal extinction at the End-Pliocene supernova. Astrobiology, 19(6), 825-830. – https://ve42.co/Melott1 Thomas, B. C. et al. (2016). Terrestrial effects of nearby supernovae in the early Pleistocene. The Astrophysical Journal Letters, 826(1), L3 – https://ve42.co/Thomas1 Melott, A. L., & Thomas, B. C. (2019). From cosmic explosions to terrestrial fires?. The Journal of Geology, 127(4), 475-481. – https://ve42.co/Melott2 Fields, B. et al. (2019). Near-Earth supernova explosions: Evidence, implications, and opportunities. arXiv preprint arXiv:1903.04589. – https://ve42.co/Fields1 Thomas, B. C., Atri, D., & Melott, A. L. (2021). Gamma-ray bursts: not so much deadlier than we thought. Monthly Notices of the Royal Astronomical Society, 500(2), 1970-1973. – https://ve42.co/Thomas2 Melott, A. et al. (2004). Did a gamma-ray burst initiate the late Ordovician mass extinction?. International Journal of Astrobiology, 3(1), 55-61. – https://ve42.co/Melott3 Firestone, R. B. (2014). Observation of 23 supernovae that exploded less than 300 pc from Earth during the past 300 kyr. The Astrophysical Journal, 789(1), 29. – https://ve42.co/firestone1 Janka, H. T. (2017). Neutrino emission from supernovae. arXiv preprint arXiv:1702.08713. – https://ve42.co/Janka1 Janka, H. T., & Hillebrandt, W. (1989). Neutrino emission from type II supernovae-an analysis of the spectra. Astronomy and astrophysics, 224, 49-56. – https://ve42.co/Janka2 Janka, H. T. (2017). Neutrino-driven explosions. arXiv preprint arXiv:1702.08825. – https://ve42.co/Janka3 Karam, P. A. (2002). Gamma and neutrino radiation dose from gamma ray bursts and nearby supernovae. Health physics, 82(4), 491-499. – https://ve42.co/Karam1 Melott, A. L., Thomas, et al.. (2017). A supernova at 50 pc: effects on the Earth's atmosphere and biota. The Astrophysical Journal, 840(2), 105. – https://ve42.co/Melott4 Ludwig, P., et al. (2016). Time-resolved 2-million-year-old supernova activity discovered in Earth’s microfossil record. Proceedings of the National Academy of Sciences, 113(33), 9232-9237. – https://ve42.co/Ludwig1 Gritschneder, et al. (2011). The supernova triggered formation and enrichment of our solar system. The Astrophysical Journal, 745(1), 22. – https://ve42.co/Gritschneder1 Motizuki, Y., Takahashi, et al. (2009). An Antarctic ice core recording both supernovae and solar cycles. arXiv preprint arXiv:0902.3446. – https://ve42.co/Motizuki Zucker, C. et al. (2022). Star formation near the Sun is driven by expansion of the Local Bubble. Nature, 601(7893), 334-337. – https://ve42.co/Zucker1 Hirata, K. et al.(1987). Observation of a neutrino burst from the supernova SN1987A. – https://ve42.co/Hirata1 Hayes, L. A., & Gallagher, P. T. (2022). A Significant Sudden Ionospheric Disturbance Associated with Gamma-Ray Burst GRB 221009A. Research Notes of the AAS, 6(10), 222. ▀▀▀ Special thanks to our Patron supporters: James Sanger, Louis Lebbos, Elliot Miller, Brian Busbee, Jerome Barakos M.D., Amadeo Bee, TTST, Balkrishna Heroor, Chris LaClair, John H. Austin, Jr., OnlineBookClub.org, Matthew Gonzalez, Eric Sexton, John Kiehl, Diffbot, Gnare, Dave Kircher, Burt Humburg, Blake Byers, Evgeny Skvortsov, Meekay, Bill Linder, Paul Peijzel, Josh Hibschman, Mac Malkawi, Mike Schneider, John Bauer, jim buckmaster, Juan Benet, Sunil Nagaraj, Richard Sundvall, Lee Redden, Stephen Wilcox, Marinus Kuivenhoven, Michael Krugman, Cy 'kkm' K'Nelson, Sam Lutfi ▀▀▀ Written by Petr Lebedev & Derek Muller Edited by Fabio Albertelli Animation by Fabio Albertelli, Jakub Misiek, Alex Drakoulis, Ivy Tello, Mike Radjabov, and Charlie Davies Filmed by Derek Muller Additional Research by Kovi Rose & Katie Barnshaw Video/photos supplied by NASA, ESA, Pond5, and Getty Images Music from Epidemic Sound & Jonny Hyman Produced by Derek Muller, Petr Lebedev, and Emily Zhang