Invited Talk: Meteoroids, Meteors, and the NEO Impact Hazard. Clark R. Chapman Southwest Research Inst. Boulder, Colorado, USA. “Meteoroids 2007” Barcelona, Spain 9:30 a.m., Friday, 15 June 2007. Relationship between Meteoroids and the Impact Hazard.
Meteoroids, Meteors, and the NEO Impact Hazard
Clark R. Chapman
Southwest Research Inst.
Boulder, Colorado, USA
9:30 a.m., Friday, 15 June 2007
By Orbital Class
Six case studies, exemplifying the different sizes and types of impact disasters, were discussed in these terms
Cases (d), (e), and (f) involve objects of interest to meteoroid researchers.
OVER IRAN? OVER ISRAEL? HOW WOULD THE GENERALS RESPOND?
(For nominal case)
Worldwide Deaths (Annual)
Asteroid Diameter (km)
How the mortality will diminish from the three kinds of impacts as the Spaceguard telescopic searches continue
Model of 30 m NEA 1998 KY26 (radar)
This will be a vital issue for decision-makers
Incremental numbers: 0.5 mag. Intervals centered on listed mag. and size.
Data courtesy A. Harris (June 2007)
H Diam. (km) Known Now SG1 (goal) SG2 (goal)
No. % of Tot. No. % of Tot. No. % of Tot.
17.75 1.0 234 59 280 83 333 98
22.02 0.14 162 3.5 450 9 4000 83
24.26 0.05 147 0.09 1200 0.6 80000 40
25.36 0.03 85 0.01 640 0.08 2 million 20
27.75 0.01 17 1e(-6) 200 1e(-5) 400000 2
29.26 0.005 6 3e(-8) 30 3e(-7) 200000 0.2
Data from Gehrels (1970)
Burbine et al (2001)
Ivezic et al (2002)
Tedesco et al. 2005
Bernstein et al. 2004
NASA SDT 2003
NEAR Laser Altimeter: Eros
Neumann & Barnouin-Jha 2005
Korycansky & Asphaug 2005
NEAR XRS data suggest Eros composition ~ ordinary chondrites
Lim et al. 2005
In the extremely unlikely event that it will hit, ground-zero will be somewhere on the red line
Rocky, metallic, no active geology, cratered, collisional fragments, some differentiated by heating
Icy, under-dense, no active geology, pristine…until they come close to the Sun, become very active, disintegrate
Under-dense, rubble piles, many volatile-rich (except at surfaces), some non-impact geology, many satellites; NEAs tidally evolved
Active, fluffy, evolved bodies with complex geology (impact & non-impact), easily split; precursor KBOs have satellites, interior “oceans”
The Little Prince
Meteorite punctured roof in Canon City, CO