Asteroid Mitigation Strategy. By Emily Reit, Trevor Barton, Mark Fischer, Eric Swank, and Garrett Baerr

Transcription

1 Asteroid Mitigation Strategy By Emily Reit, Trevor Barton, Mark Fischer, Eric Swank, and Garrett Baerr

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3 Impact History 65 mya- End of the Jurassic Period 3.3 mya- Impact in Argentina 50,000 ya- Barringer Crater in Arizona 1490 AD- 10,000 people die in Chiling-yang, China 1908 AD- Tunguska, Siberia 1937 AD- Asteroid Hermes narrowly misses Earth

4 Tunguska's Possible Relative Impact Size

5 Threats 1994 Comet Shoemaker-Levy 9 Incident Comet that broke apart and smashed into Jupiter SL9 fragments ranged in size from a few hundred metres to a couple of kilometres across Original comet's nucleus up to 5 km

6 Shoemaker was a turning point. If it can happen in front of your nose practically in your backyard-- it can also happen on Earth". -Benny Peiser -Liverpool s John Moore s University at the American Association for the Advancement of Science meeting in 2000

7 Recent Findings 2008: NASA reports approximately 5,600 Near Earth Objects 967 are Potentially Hazardous Asteroids Objects 150 m or larger which come w/in 0.05 astronomical units (about 7.5 million km) of Earth Search programs over the next 15 years will add to the NEO database 200,000 to 400,000 potential impactors

8 Current Committees The United Nations Committee on the Peaceful Uses of Outer Space (COPUOS) The Mission Planning and Operations Group (MPOG) NASA ASE (Association of Space Explorers Secure World Foundation United Nations Platform for Space-based Information for Disaster Management and Emergency Response

9 Asteroid Threats: A Call For Global Response Submitted for consideration and subsequent action by the United Nations A report on the need to develop an international decision-making program for global response to Near Earth Object threats. Three Part Consideration: Information Gathering, Analysis, and Warnin Mission Planning and Operations Mission Authorization and Oversight Group

10 Things to Consider Responsibility Consequences Timing Information Sharing Cooperation

11 International Effect Capabilities Discovery Why? The Sooner the Better o Lead Time o Delays Limit Options

12 Detection Goals Near Earth Object (NEO) Survey Program (2005) o Detect, catalogue and characterize 90% of PHO's by 2020 o Asteroids greater than 140 meters within.05 AU of Earth National Research Council (2008) o Asked to find best strategy to complete this goal o Impossible under current funding Current funding $4 million, asking $16 million

13 Current Detection Ground-based telescopes o Charged Couple Devices (CCDs) - digital images of sky o Compare relative location, direction and brightness - streaks o Requires a clear, night sky RAPTOR o Stereo vision to measure parallax - objects heading for Earth Yarkovsky Effect o Heating and cooling from sun o Impact on orbit in the long run Radar - Arecibo, Goldstone o Close-range classification and refined tracking

14 Future of Detection Infrared space-telescopes o Eliminates albedo problem - size measurements o No need for clear, night sky Pan-STARRS - Maui High Performance Computer Center o 1.4 Gigapixel Camera - detects objects 100x fainter o Higher spatial resolution - can see through cluttered regions o 3-16x more effective than current NEO telescopes Improved telescopes, radar o RAPTOR, 1 meter telescopes would increase warning by many times o Help to characterize from further distances

15 Ok, So We Found An Asteroid Source: CSA 2005 Planetary Defense Report

16 Short Term Mitigation Strategies Harsh reality of limited resources and time o Social and political challenges in this situation Actions on the Asteroid o Deflection or Destruction Deflection is the best solution, but more difficult o Nuclear or Kinetic Nuclear weapons can be detonated off the surface, on the surface, or in the interior Kinetic weapons are simpler, but less effective Ground-based responses o Mapping of impact location and timing o Evacuation and shelter construction Long-term vs. short-term shelter design depends on the characterization of the impact event

17 Mitigation Strategies Comparison All strategies are a function of the asteroid characterization Source: CSA 2005 Planetary Defense Report

18 Long Term Threat Mitigation Instantaneous Force Method (IF) o o Projectile Into Asteroid Explosive (Nuclear Missile) Too Unpredictable Continuous Force Method (CF) o o o Ion Thruster Electrostatic (Coulomb Force) Mass Driver Electromagnetic Catapult Gravity Tractor Gravitational Field

19 Risk Corridor Potential Impact Zone Wavy Due to Tilt of Earth Probability Usually 1:1000 to 1:1,000,000 Raises More Political Issues

20 Asteroid Misses Earth o Keyholes Gravity Puts it on a Collision Course for Earth in the Future Usually Adds at Least a Few Years 2011 AG5 passes in 2023 o Could Keyhole into 2040

21 "The dinosaurs became extinct because they didn't have a space program. And if we become extinct because we don't have a space program, it'll serve us right!" -Arthur C. Clarke