Abstract
The two essential functions of planetary defense are to locate any asteroid on a collision course with Earth and to deflect or destroy it before it hits. Short-term warning and evacuation may be sufficient to protect populations from small asteroids. If active defense is required, we may either deflect the asteroid (change its orbit so that it misses the Earth or strikes in an uninhabited area such as oceans or deserts) or break it up far enough from Earth that the debris is dispersed and misses the planet. Most defense strategies involve deflection using spacecraft to intercept the asteroid, preferably several years before the predicted impact, to produce a change in its orbital period. The technologies that have been studied use kinetic impactors, nuclear explosives, or gravity tractors. None of these has been demonstrated yet, although the DART mission under development will test kinetic impact technology. Other suggestions, such as laser or solar heating or various slow-push options, are not technologically mature enough to be considered. Because dangerous impacts are exceedingly rare, with intervals of centuries or longer, we must also consider the potential unintended consequences or even deliberate misuse of premature development or deployment of planetary defense systems.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
Ahrens, T. J., & Harris, A. W. (1992). Deflection and fragmentation of near-Earth asteroids. Nature, 360(6403), 429–433. doi:https://doi.org/10.1038/360429a0
Ahrens, T. J., & Harris, A. W. (1994). Deflection and fragmentation of NEAs. In GehrelsT. (Ed.), Hazards Due to Comets and Asteroids (pp. 897–928). Tucson: University of Arizona Press.
Barbee, B. W., Syal, M. B., Dearborn, D., Gisler, G., Greenaugh, K., Howley, K. M., et al. (2018). Options and uncertainties in planetary defense: Mission planning and vehicle design for flexible response. Acta Astronautica, 143(August 2017), 37–61. doi:https://doi.org/10.1016/j.actaastro.2017.10.021
Canavan, G. H. (1994). Cost and benefit of near-Earth object detection and interception. In T. Gehrels (Ed.), Hazards Due to Comets and Asteroids (pp. 1157–1191). Tucson: University of Arizona Press.
Chapman, C. R., Durda, D. D., & Gold, R. E. (2001). The comet/asteroid impact hazard, a systems approach. San Antonio, TX: Southwest Research Institute.
Cheng, A. F., Rivkin, A. S., Michel, P., Atchison, J., Barnouin, O., Benner, L., et al. (2018). AIDA DART asteroid deflection test: Planetary defense and science objectives. Planetary and Space Science, 157, 104–115. doi:https://doi.org/10.1016/j.pss.2018.02.015
Chodas, P. (1999). Orbit uncertainties, keyholes, and collision probabilities. In Bulletin of the American Astronomical Society (Vol. 31, p. 1117).
Gritzner, C., & Kahl, R. (2004). Mitigation technologies and their requirements. In M. Belton, T. Morgan, N. Samarasinha, & D. Yeomans (Eds.), Mitigation of Hazardous Comets and Asteroids (pp. 167–200). Cambridge University Press.
Harris, A. W. (2018). Population and impact frequency of Tunguska-size NEAs (in press). Icarus.
Harris, A. W., Canavan, G. H., Sagan, C., & Ostro, S. J. (1994). The deflection dilemma: Use vs. misuse of technologies for avoiding interplanetary hazars. In T. Gehrels (Ed.), Hazards Due to Comets and Asteroids (pp. 1145–1156). Tucson: University of Arizona Press.
Harris, A. W., Barucci, M. A., Cano, J. L., Fitzsimmons, A., Fulchignoni, M., Green, S. F., et al. (2013). The European Union funded NEOShield project: A global approach to near-Earth object impact threat mitigation. Acta Astronautica, 90(1), 80–84. doi:https://doi.org/10.1016/j.actaastro.2012.08.026
Holsapple, K. (2004). About deflecting asteroids and comets. In M. Belton, T. Morgan, N. Samarasinha, & D. Yeomans (Eds.), Mitigation of Hazardous Comets and Asteroids (pp. 113–140). Cambridge University Press.
Lu, E. T., & Love, S. G. (2005). Gravitational tractor for towing asteroids. Nature, 438(7065), 177.
Melosh, H. L., Nemenchinov, I. V., & Zetzer, Y. I. (1994). Non-nuclear strategies for deflecting comets and asteroids. In T. Gehrels (Ed.), Hazards Due to Comets and Asteroids (pp. 1111–1132). Tucson: University of Arizona Press.
Milani, A., Chesley, S. R., Chodas, P. W., & Valsecchi, G. B. (2002). Asteroid close approaches: Analysis and potential impact detection. In W. F. Bottke (Ed.), Asteroids III (pp. 55–70). Tucson: University of Arizona Press.
Morrison, D. (2005). Defending the Earth Against Asteroids: The Case for a Global Response. Science & Global Security, 13(1–2), 87–103.
Morrison, D., & Teller, E. (1994). The Impact Hazard: Issues for the Future. In T. Gehrels (Ed.), Hazards due to Comets and Asteroids (pp. 1135–1143). Tucson: University of Arizona Press.
Morrison, D., Harris, A. W., Sommer, G., Chapman, C. R., & Carusi, A. (2002). Dealing with the impact hazard. In W. F. Bottke (Ed.), Asteroids III (pp. 739–754). Tucson: University of Arizona Press.
Sagan, C., & Ostro, S. J. (1994). Long-range consequences of interplanetary collisions. Issues in Science and Technology, 10(4), 67–72.
Schweickart, R. L. (2004). The real deflection dilemma. In AIAA Planetary Defense Conference (p. AIAA-2004-1467).
Shapiro, I. I., Vilas, F., A’Hearn, M., Cheng, A. F., Abell, P., Benner, L. a. M., et al. (2010). Defending Planet Earth. Washington, D.C.: National Academies Press. doi:https://doi.org/10.17226/12842
Simonenko, V., Nogin, V., Petrov, D., Shubin, O., & Solem, J. C. (1994). Defending the Earth against impacts from large comets and asteroids. In T. Gehrels (Ed.), Hazards Due to Comets and Asteroids (pp. 929–954). Tucson: University of Arizona Press.
Solem, J. C. (2000). Deflection and disruption of asteroids on collision course with Earth. Journal of the British Interplanetary Society, 53, 180–196.
Valsecchi, G. B., Milani, A., Gronchi, G. F., & Chesley, S. R. (2003). Resonant returns to close approaches: Analytical theory. Astronomy & Astrophysics, 408(3), 1179–1196.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2019 Springer Nature Switzerland AG
About this chapter
Cite this chapter
Morrison, D. (2019). Overview of Active Planetary Defense Methods. In: Schmidt, N. (eds) Planetary Defense. Space and Society. Springer, Cham. https://doi.org/10.1007/978-3-030-01000-3_7
Download citation
DOI: https://doi.org/10.1007/978-3-030-01000-3_7
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-030-00999-1
Online ISBN: 978-3-030-01000-3
eBook Packages: Political Science and International StudiesPolitical Science and International Studies (R0)