Previously,

1. Previously, at Bolides 2009 Prague...

2. Sky-plane probability distribution for impactors 30 days before impact with V < 22.7 and apparent motion < 12 deg/day Vereset al. (2009)

3. Sky-plane probability distribution for 3 meterdiameter impactors(bolides) 1 day before impact 2008 TC3 with V < 22.7 and apparent motion < 12 deg/day Vereset al. (2009)

4. impactor discoveries in a4 year PS1 survey mission Vereset al. (2009) 1 night tracklet 3 night orbit

5. impactor discoveries in a4 year PS1 survey mission Vereset al. (2009) So how did CSS find 2008 TC3? • they got ‘lucky’ or • there are more small impactors than expected or • something is wrong with our simulation 1 night tracklet 3 night orbit

6. A • John Tonry, PI • 8 telescopes and cameras • 25cm aperture, f/2.8, 5° FOV, 20 deg2 • 4x4k pixels at 4.4”/pix • 30s exp, 4s readout, 10e- read-noise • Sensitivity at SNR=5 • V=19.3 1 telescope, 1 exp, red & blue • V=20.0 4 telescope, 4 exp, red & blue • Deployment • 2 pairs x 2 pointingsx 2 sites • “blue” (g+r) and “red” (r+i) filters • 2 observations of 20,000 deg2/night STEROID T ERRESTRIALIMPACT L AST A LERT S YSTEM

7. A STEROID T ERRESTRIALIMPACT L AST A LERT S YSTEM

8. A STEROID T ERRESTRIALIMPACT L AST A LERT S YSTEM

9. A Ironwood Observatory STEROID T ERRESTRIALIMPACT L AST A • portable • robotic • autonomous LERT S YSTEM

10. A • Cost • ≈ $2M construction for 2 sites • ≈ $0.5M/year operations • ≈ $1Mincremental/site • Time • 2 years from start of funding STEROID T ERRESTRIALIMPACT L AST A LERT S YSTEM

11. A • Asteroid collisions • 10m MB asteroid disruption/day • 100m MB asteroid disruption/year • 1000m dust cloud visible in MB • Light curves • ~400 photometric observations/yearfor ~105asteroids • Bolides • Onebolide like 2008 TC3 per year STEROID T ERRESTRIALIMPACT L AST A LERT S YSTEM

12. A T L ATLASwill identify>60% of allimpactors A S

13. A STEROID T ERRESTRIALIMPACT L AST A LERT S YSTEM