Stephen Hawking thought an asteroid impact posed the greatest threat to life on Earth. Thanks to Kiwico for sponsoring this video. For 50% off your first month of any crate, go to https://kiwico.com/veritasium50

For other potential world ending catastrophes, check out Domain of Science: https://ve42.co/DoS

Special thanks to:

Prof. Dave Jewitt from UCLA Earth, Planetary, and Space Sciences

Prof. Mark Boslough from Sandia National Labs

Scott Manley: https://www.youtube.com/user/szyzyg

Ryan Wyatt at Morrison Planetarium

Prof. Amy Mainzer

Alexandr Ivanov for the opening shot of Chelyabinsk Meteor

Maps of Asteroid Impacts —https://ve42.co/Map

Time passing animation from Universe Sandbox - http://universesandbox.com/

Opposition Effect — https://ve42.co/Belskaya2000

Belskaya, I. N., & Shevchenko, V. G. (2000). Opposition effect of asteroids. Icarus, 147(1), 94-105.

Potentially Hazardous Asteroids — https://ve42.co/Perna2013

Perna, D., Barucci, M. A., & Fulchignoni, M. (2013). The near-Earth objects and their potential threat to our planet. The Astronomy and Astrophysics Review, 21(1), 65.

Survey of Potentially Hazardous Asteroids — https://ve42.co/NEOSurvey

Population Vulnerability — https://ve42.co/Rumpf2017

Rumpf, C. M., Lewis, H. G., & Atkinson, P. M. (2017). Population vulnerability models for asteroid impact risk assessment. Meteoritics & Planetary Science, 52(6), 1082-1102.

Size distribution of NEOs — https://ve42.co/Trilling17

Trilling, D. E., Valdes, F., Allen, L., James, D., Fuentes, C., Herrera, D., ... & Rajagopal, J. (2017). The size distribution of near-earth objects larger than 10 m. The Astronomical Journal, 154(4), 170.

2020 NEOWISE Data Release — https://ve42.co/NEOWISE

National Research Council Report— https://ve42.co/Defending

Board, S. S., & National Research Council. (2010). Defending planet earth: Near-Earth-Object surveys and hazard mitigation strategies. National Academies Press.

Tug Boat — https://ve42.co/Schweickart03

Schweickart, R. L., Lu, E. T., Hut, P., & Chapman, C. R. (2003). The asteroid tugboat. Scientific American, 289(5), 54-61.

Gravity Tractor 1 — https://ve42.co/Lu05

Lu, E. T., & Love, S. G. (2005). Gravitational tractor for towing asteroids. Nature, 438(7065), 177-178.

Laser Ablation — https://ve42.co/Thiry14

Thiry, N., & Vasile, M. (2014). Recent advances in laser ablation modelling for asteroid deflection methods. SPIE Optical Engineering+ Applications, 922608-922608.

Yarakovsky Effect — https://ve42.co/Yara

DART Mission — https://ve42.co/DART

Nuclear 1 — https://ve42.co/Ahrens92

Ahrens, T. J., & Harris, A. W. (1992). Deflection and fragmentation of near-Earth asteroids. Nature, 360(6403), 429-433.

Nuclear 2 — https://ve42.co/Bradley10

Bradley, P. A., Plesko, C. S., Clement, R. R., Conlon, L. M., Weaver, R. P., Guzik, J. A., ... & Huebner, W. F. (2010, January). Challenges of deflecting an asteroid or comet nucleus with a nuclear burst. In AIP Conference Proceedings (Vol. 1208, No. 1, pp. 430-437). American Institute of Physics.

Researched and Written by Petr Lebedev, Jonny Hyman and Derek Muller

3D animations, VFX, SFX, Audio Mixing by Jonny Hyman

2D animation by Ivàn Tello

Intro animation by Nicolas Pratt

With Filming by Raquel Nuno

Music from https://epidemicsound.com "Stellar Dance" "Orbit" "That Notebook" "What We Discovered" "Out of Poppies" "Handwriting"

Images and video supplied by Getty Images