NEO Detonation Strategies

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NEO Detonation Strategies

• Adriana Alcorta
• Kacie Constantine
• Lauren Goldstein
• Dayna Hardtman
• Alicia Aarnio

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As of now, there is no formal mitigation
procedure.
The prime impediment is the lack of assigned
responsibility or authority to any person or
organization either to plan for mitigation or to
deal with a specific threat if one develops.--
AIAA Planetary Defense Conference 23-26 Feb 2004
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Methods of Detonation
1. Nuclear Energy
http//www.au.af.mil/au/2025/volume3/chap16/v3c16-
3c.htmfigure203-4

• Nuclear explosives would provide the most
  efficient source of energy (a million times more
  than chemical explosives).

II. This is the only viable option we have now,
although safety implications are unpleasant.
III. Legally, nuclear explosions cannot take
place in space.
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Nuclear Detonation

• Why Nuclear Detonation?
• Most powerful explosive method by volume
• Most highly developed technology
• Only feasible option for large NEOs
• Can work with relatively short notice

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How it Works

• Standoff detonation
• The explosion is released above the asteroid and
  is struck by radiation waves
• A nuclear explosive would be launched at the NEO
  from Earth of from an unmanned orbiter.

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Dangers

• The obvious danger is that we could fail in
  safely launching the nuclear material out of
  Earths atmosphere, thereby causing catastrophe.
• Whether or not that sort of danger is worthwhile
  depends of the expected damage of the object.
• Once broken apart, Earth could be hit by many
  smaller pieces, actually increasing the damage.
  (though our atmosphere would protect us, unlike
  the Petit Prince, whos planet appears to have no
  atmosphere at all)

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Methods of Detonation
2. Kinetic Energy
http//www.au.af.mil/au/2025/volume3/chap16/v3c16-
3c.htmfigure203-4

• Employ a spacecraft into typical orbit speeds.
  Its specific energy would be one hundred times
  that of a high explosive.

II. However, in order to make a sufficient impact
on NEO spacecraft would have to be
unrealistically large and therefore this is not a
feasible option.
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Why Kinetic Energy?

• Can project kinetic energy over interplanetary
  distances.
• All requiste technologies exist.
• Effects of kinetic energy against NEOs are
  understood up to 15 km/sec

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What Kinetic Energy Does

• Impactor strikes the NEO and creates a hydro
  dynamically induced crater and internal shock
  wave.
• Can the cause somekind of target body response.

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Kinetic energy not Efficient

• Works with small asteroids that are about 100 m
  or less in size
• Spacecraft would have to be really large
• Debris would hit surface of the earth

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Methods of Detonation
3. Solar Energy
http//www.au.af.mil/au/2025/volume3/chap16/v3c16-
3c.htmfigure203-4

• Large inflatable mirrors have already been
  constructed. Use these in order to evaporate
  asteroids or masses around the size of one
  kilometer.

II. Practical problems include degradation of
the optical system by outflowing hot gas and
dust--AIAA Planetary Defense Conference 23-26
Feb 2004
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Safest Solution?
Would not cause amounts of debris that are
precipitated with using nuclear and kinetic
detonation, but could possibly emit dangerous
gases in the atmosphere.
Using the suns resources only expense would be
in creating apparatus. However, technology still
needs to be researched.
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The Dangers of Detonation
Danger of debris from explosion. Of course,
debris could be present in deflection processes
also.
NEOs that explode in the Earth's atmosphere
several times every year could be mistaken for a
nuclear detonation in times of international
tension, triggering an unwarranted response.
--The prepared statement of Brigadier General
Worden, October 3, 2002.
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Good idea or bad idea?

• A single, 2 km, rocky asteroid at 30km/s would
  release 1 million MT of TNT of Energy, and cause
  a 9.6 earthquake.

• One impact would cause a large tsunami that would
  dissipate its energy radially over the nearest
  land.

• Several impacts would cause the waves to
  interfere with one another the larger
  distribution would cause more total damage.

• 1km fragments, 8 total would release the same
  amount of energy, but each would produce an
  earthquake of 9.0 on the Richter scale.

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The Challenges

• Compositions of objects not well known
• Difficult to track many smaller objects
• Advance detection is necessary for successful
  interception objects large enough to do
  significant damage can go undetected until its
  too late. Quickly moving comets would most
  likely not be seen coming

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How reliable is detonation?

• Object breakup is hard to determine without
  knowledge of composition
• After breakup, we cannot predict behavior of
  fragments
• We may blow the NEO out of our resolution and
  thus not know if any fragments were coming our
  way until too late

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International agreements and resolutions
affecting our mitigation response.
http//www.llnl.gov/planetary/pdfs/Integration/06-
Tedeschi.pdf
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A Question of Ethics A number of possible
mechanisms have been considered for deflecting or
breaking up potentially hazardous Near Earth
Objects most would require the use of a
spacecraft with some means of transferring energy
or momentum to the object, for example by kinetic
energy transfer (by heavy projectiles carried on
the spacecraft or by causing a collision between
asteroids), by chemical or nuclear explosives, or
even by mounting "sails" on the object to harness
the Sun's radiation pressure. -The
Task Force on Potentially Hazardous Near Earth
Objects
Risks Uncertainty of Harnessing Any Kind of
Energy Kinetic Energy Solar Energy Nuclear
Energy
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Nuking Those Nasty NEOs!
Potential Consequences Political
Social/Environmental Economic
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Practicality vs. Ethics
Destruction or Deflection Ex Nuclear
Warhead vs. Pulse Propulsion
Most Relevant Questions What method is most
financially feasible? What method is most
technologically realistic?
If one day in the future we discover that an
asteroid is big enough to cause mass extinction
is going to hit Earth, and then we alter the
course of that asteroid, so that it does not hit
us, it will be one of the most important
accomplishments in all of humankind. -George
Brown, Chairmen of the Committee of Space Science
Technology
If this is true, than it may be important for
humankind to ask Which method is most morally
appropriate?
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We know why the dinosaurs died out. It was
because they didn't have a space program. James
Oberg