Asteroids
Existential risk from asteroids refers to the potential for a catastrophic event due to a large asteroid or comet colliding with Earth. While the probability of such an event is low in any given year, the potential consequences are so severe that it warrants serious attention.
A significant asteroid impact could cause massive destruction and loss of life, particularly if it occurred near a populated area. The resulting dust and debris thrown into the atmosphere could also lead to a "nuclear winter" scenario, with serious global climatic effects that could last for years and profoundly impact agriculture and ecosystems.
Moreover, the global response capabilities to such a threat are currently quite limited. Detecting near-Earth objects (NEOs) early enough to deflect or destroy them is a significant technical and logistical challenge. There is also the need for international cooperation and coordination, given that the impact of a large NEO would have global implications.
Addressing the existential risk from asteroids involves several strategies. First, we need to improve our capabilities for detecting and tracking NEOs. Organizations like NASA's Planetary Defense Coordination Office and the international Spaceguard survey are working on this, but there is always room for improvement and expansion.
Second, we need to develop viable methods for asteroid deflection or destruction. Various techniques have been proposed, from nuclear detonation to gravitational tractor methods, but they all require further research and testing.
Third, we need to promote international cooperation and develop a global response plan for potential asteroid threats. This includes agreeing on who is responsible for launching a deflection mission and how the costs and potential consequences are to be shared among nations.