Planetary Defense

Why is Planetary Defense Important?

Planetary Defense

The Danger to Earth

  • We live in a shooting gallery. Ever since Earth was formed, it has been the target of millions of asteroids and comets that also orbit the sun and come close to or cross Earth's orbit. Many of those, termed Near Earth Objects, were swept up and crashed into Earth's surface over the millennia. The larger objects struck Earth with devastating force, often forming large craters, evidence of which can still be seen today in the world's landscape.
  • Lighting the Sky. Although our planet has swept up many NEOs over the millennia, some still threaten Earth. Every day, small orbiting rocks (up to about 10 m across) called meteoroids enter Earth's atmosphere, leaving a bright streak behind as they burn up. The larger meteoroides may burn up in a spectacular explosion, lighting the night sky for many miles around. Because they are so spectacular, these "bolides" often generate many panicky calls to emergency authorities. Despite their awesome appearance in the atmosphere, because most of the material burns up, they almost never cause damage to people on Earth.
  • Risks of Asteroids. The NEOs that most concern Earth are the Potentially Hazardous Asteroids (PHAs) whose orbits cross Earth's and have a relatively high potential of impacting Earth itself. The damage they could do depends on their size and the trajectory they follow in striking Earth, with damage ranging from destruction of an area the size of a city, to creation of tsunamis, to the extinction of almost all life on Earth.
  • Defending the Planet. Planetary Defense includes finding these PHAs, predicting their future locations, and providing warning about future impacts with the Earth. It also includes missions to deflect impacting asteroids by changing their orbit, and disaster preparedness, management, and recovery on Earth to mitigate their consequences.

Secure World Foundation's Role in Planetary Defense

  • Appropriate Governance. The Foundation is primarily concerned with the non-technical aspects of Planetary Defense, focusing especially on how the world might organize to meet the challenge of mitigating possible effects of an incoming NEO. NEOs pose a threat to the entire planet, and dealing with them requires cooperation and coordination between States. Planetary Defense poses significant policy and legal challenges which echo some of the same problems found in other areas of the outer space realm. These include space situational awareness, data sharing, collective security, and shared decision making.
  • Facilitation and Information Sharing. The Foundation works as a facilitator and information source among States, international bodies, and national space agencies to promote dialog and cooperation. It also looks for opportunities to leverage relevant lessons from the Planetary Defense problem to other space and international issues. The Foundation has a strong interest in contributing to the important task of creating an internationally agreed-upon plan and guidelines for responding to a NEO threat. Hence, the Foundation has partnered with the Association of Space Explorers and other organizations to assist the Committee on the Peaceful Uses of Outer Space to develop an appropriate international agreement for responding to the NEO threat.


Last updated on July 16, 2013