Planetary defense

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Planetary defense, or planetary defence, is the concept of protecting Earth or another planet from extra-terrestrial threats (meaning any threat that originates outside of the earth).

1 Near-Earth objects
2 Other threats
3 Science fiction
- 3.1 Selected works
4 External links

[edit] Near-Earth objects

The most-recognized planetary threat is Near-Earth asteroids and other Near-Earth objects. If a large asteroid collided with Earth, such an impact event might bring about the end of civilization.

The Planetary Defense Conference was held beginning on 23 February 2004 to discuss detection, deflection, policy, law, and disaster preparedness.

The first step in defending against Near-Earth objects is detection and threat analysis. Programs include:

If these programs operate correctly, we can expect years advance notice before an asteroid would impact Earth. Various asteroid deflection strategies have been proposed that may be implemented in such an event.

U.S. Representative George E. Brown, Jr. (D-CA) was quoted as voicing his support for planetary defense projects in Air & Space Power Chronicles, saying "If some day in the future we discover well in advance that an asteroid that is big enough to cause a mass extinction is going to hit the Earth, and then we alter the course of that asteroid so that is does not hit us, it will be one of the most important accomplishments in all of human history."

Because of Congressman Brown's long-standing commitment to planetary defense, a recent U.S. House of Representatives' bill, H.R. 1022, was named in his honor: The George E. Brown, Jr. Near-Earth Object Survey Act. This bill "to provide for a Near-Earth Object Survey program to detect, track, catalogue, and characterize certain near-earth asteroids and comets" was introduced in March 2005 by Rep. Dana Rohrabacher (R-CA). It was eventually rolled into S.1281, the NASA Authorization Act of 2005. Presently, it is law.

[edit] Other threats

There is also some speculation about defending against alien invasion, though this is typically in the science fiction realm, as extraterrestrial life's existence is unknown.

A recent textbook by Dr. Travis S. Taylor, Dr. Bob Boan, R.C. Anding, and Dr. T. Conley Powell entitled An Introduction to Planetary Defense A Study of Modern Warfare Applied to Extra-Terrestrial Invasion offers some insight, details, and analysis of how humanity might defend itself against an alien invasion.

[edit] Science fiction

Planetary defenses are a recurring theme in science fiction, usually designed to repel an invasion of a planet by an external force; human or otherwise. An example would be during the Earth Alliance Civil War on the television series Babylon 5, whereby the loyalist forces used orbital planetary defense platforms to defend Earth from the separatist forces.

Planetary defenses are not limited to one pre-defined type, some are space or orbital based platforms or ships like in the previously stated example, there are also weapon systems based on the surface of the said planet, as in Stargate SG-1 where the hero uses an Ancient weapon in Antarctica to destroy the villain's invading fleet; others are more simple, including ground based fighters, as in the case in Star Wars Episode IV: A New Hope where single-manned fighters defended a rebel base against a moon-sized Death Star.

The Posleen novels also called the Legacy of the Aldenata series by John Ringo describe in detail a planetary defense scenario using alien technology to construct a fleet of starships. Similar themes can be seen in the animated series Robotech. Robotech also includes a "Grand Cannon" based in the northern hemisphere that is used for planetary defense. Doc Travis S. Taylor's Warp Speed and The Quantum Connection books (known as the Warp War series) gives examples of developing planetary defense systems based on warp technologies. The Von Neumann's War series by John Ringo and Travis S. Taylor also develops an organization designed to develop planetary defense strategies from present day technologies.