Clark R. ChapmanSouthwest Research Inst.Boulder, Colorado, USA

Clark R. ChapmanSouthwest Research Inst.Boulder, Colorado, USA

3232ndnd Session of Erice International Seminars Session of Erice International Seminars on Planetary Emergencieson Planetary Emergencies

Erice, Italy 25 August 2004Erice, Italy 25 August 2004

3232ndnd Session of Erice International Seminars Session of Erice International Seminars on Planetary Emergencieson Planetary Emergencies

Erice, Italy 25 August 2004Erice, Italy 25 August 2004

Report to “Cosmic Objects PMP” on AIAA/B612 Planetary Defense Workshop

Report to “Cosmic Objects PMP” on AIAA/B612 Planetary Defense Workshop

http://www.boulder.swri.edu/clark/clark.html

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/

The Four DEFT Scenarios: Other Considerations

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

Remember: an impact scenario is unprecedentedunprecedented 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…

http://www.aero.org/conferences/planetdef/Impact_Scenarios.pdf

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.

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.

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

Palmer Divide ObservatoryPalmer Divide Observatory

Brian MarsdenBrian Marsden

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

In the Post 9/11 World...

What are the potential What are the potential consequences of the consequences of the remote threat of an remote threat of an asteroid impact catastrophe?asteroid impact catastrophe?