Clark R. Chapman Southwest Research Inst. Boulder, Colorado, USA

1. http://www.boulder.swri.edu/clark/clark.html Report to “Cosmic Objects PMP” on AIAA/B612 Planetary Defense Workshop Clark R. Chapman Southwest Research Inst. Boulder, Colorado, USA 32nd Session of Erice International Seminars on Planetary Emergencies Erice, Italy 25 August 2004

2. Planetary Defense Conference Overview • Mixed engineering/interdisciplinary emphases, sponsored by AIAA, Aerospace Corp., B612 • 4 “DEFT” scenarios offered as baseline for study months in advance • Congressman Dana Rohrabacher • Considerable media coverage (esp. AL00667) though steep fees prohibited broad participation • Post-conference “white paper” hammered out, but not adopted (yet) by AIAA • Web-site has complete videos, pdf’s: http://www.planetarydefense.info/

3. The Four DEFT Scenarios: Other Considerations Remember: an impact scenario is unprecedented in historical times; there are no protocols to deal with one, nor is there a base of experience with an impact’s unique social and physical repercussions… • Aramis is multi-km asteroid discovered with 3 decades warning; best simulates ever-changing (generally improving) knowledge of impactor and impact circumstances. • Athos is 200 m S-type (with moonlet!), 10 years • D’Artagnan is 120 m NEA, will hit Europe in just 5 years, necessitating a “crash” program • Porthos is 2x1x1 km comet, hits US in 2015 http://www.aero.org/conferences/planetdef/Impact_Scenarios.pdf

4. Major Themes of Conference • Strong emphasis on unknown physical properties, thus unpredictable behavior, of NEAs • Better understanding of technical issues involving refinement of NEA trajectory after discovery • Strong emphasis on slowly-acting pushes for deflection as distinct from blowing them up (although this was bitterly argued afterwards in drafting the white paper) • Welcome input (though less well developed) on social and political issues • Broad cultural input sets the context (Larry Niven, Oliver Morton, John Logsdon) as well as legal, economic, and policy inputs.

5. The Impact that Didn’t Happen: AL00667, 13/14 January 2004 • Nominal MPC Confirmation Page ephemeris, based on 4 LINEAR positions, suggests impact in 24 hr (few hrs after Bush space speech) • Posting noticed by amateur astronomers, discussed on Yahoo’s MPML while MPC staff, professional astronomers “in the dark” • Cloudy skies in much of Europe and USA prevent definite follow-up • Steve Chesley (JPL NEO Program Office) calculates 10% - 40% chance of impact, in northern hemisphere, during next few days of ~30 m body • Midnight considerations to report Torino Scale = 3 prediction • Lucky ad hoc e-mail connection enables amateur astronomer Brian Warner, with 20-inch telescope, to search for “virtual impactors” • Warner finds no object; LINEAR recovers object; calculations few hrs before Bush speech place it 10 times farther away, impact ruled out • Czech recovery next night provides designation 2004 AS1 LINEAR site in N.Mex.

6. Attributes of the AL00667 Case • Predicting imminent, “final plunge” impacts is not in the scope of the Spaceguard Survey (LINEAR, MPC, JPL NEO Program Office, NEODys, IAU WGNEO, etc.) • A system that notifies observers to “confirm” very preliminary NEOs necessarily makes the data public; and if data indicate a possible impact, they cannot be ignored • AL00667 positions had larger-than-usual uncertainties (we now know); but analysis of trajectories within usual uncertain-ties yielded 40% impacting the Earth; there was no mistake • But AL00667 data were delayed or held private; not available at all to experts, e.g. at Lowell Observatory, Univ. of Pisa • Is a public announcement ethically required if there is a professional calculation of >10% impact chance? • Should Bayesian statistics be folded into calculation? • Communications network for AL00667 was mainly ad hoc, unfunded, and cannot be relied on in future • Until now, only rudimentary (at best!) protocols, plans to handle out-of-scope, unexpected cases: NASA is changing! • News media did not hype (or even notice) event, until this talk The NEO Confirmation Page Brian Marsden Palmer Divide Observatory

7. Suggestions and Recommendations in Aftermath of AL00667 • Should Spaceguard infrastructure be enhanced to operate “24/7” and handle imminent impacts? • NO: mismatched priorities; only few-% chance that next small impactor will be seen before it hits • YES: only if “SDT Report” is implemented with system optimized to find smaller impactors • Should there be plans/protocols for best-effort handling of unexpected, out-of-scope cases? • YES: public expects responsible, professional responses; we were lucky this time • Instead of “one-night-stand” preliminary data being held private by LINEAR/MPC, should data be made immediately available to qualified international asteroid orbit specialists? • MPC says “NO”: unverified data can be misused • I say “YES”: preliminary, time-urgent, noisy data are normal in science; independent calculations are essence of open science. Why keep private? “SDT Report” August 22, 2003

8. In the Post 9/11 World... What are the potential consequences of the remote threat of an asteroid impact catastrophe?