1. Nick Moskovitz Lowell Observatory Nick Moskovitz Lowell Observatory Workshop on Potentially Hazardous Asteroids: Characterization, Atmospheric Entry and Risk Assessment Workshop on Potentially Hazardous Asteroids: Characterization, Atmospheric Entry and Risk Assessment Telescopic Insight into the Physical Properties of Earth-Impacting Asteroids 7 July 2015NASA Ames Research Center

2. Nick Moskovitz | Physical Properties of Potentially Earth-Impacting Asteroids Techniques and data products Current state of knowledge Ongoing characterization efforts Outline

3. Nick Moskovitz | Physical Properties of Potentially Earth-Impacting Asteroids Discovery Surveys Current major players: - Catalina Sky Survey - PanSTARRS Current major players: - Catalina Sky Survey - PanSTARRS CSS - 1.5m, 0.7m, (1.0m) PS - Two 1.8m

4. Nick Moskovitz | Physical Properties of Potentially Earth-Impacting Asteroids Discovery > 100 NEOs / month

5. Nick Moskovitz | Physical Properties of Potentially Earth-Impacting Asteroids Optical astrometry Visible photometry Thermal-IR photometry Visible and near-IR spectroscopy 3- μ m spectroscopy Characterization Techniques

6. Nick Moskovitz | Physical Properties of Potentially Earth-Impacting Asteroids Optical Astrometry Orbital Properties: a, e, i, Ω, ω Orbital Properties: a, e, i, Ω, ω Δv, MOID, v ∞ Δv, MOID, v ∞ Impact geometry Impact geometry Non-gravitational forces: Non-gravitational forces: Yarkovsky Yarkovsky Relativity Relativity Orbital Properties: a, e, i, Ω, ω Orbital Properties: a, e, i, Ω, ω Δv, MOID, v ∞ Δv, MOID, v ∞ Impact geometry Impact geometry Non-gravitational forces: Non-gravitational forces: Yarkovsky Yarkovsky Relativity Relativity

7. Nick Moskovitz | Physical Properties of Potentially Earth-Impacting Asteroids Visible Photometry Rotation periods Rotation periods Axis ratios Axis ratios Convex shape model Convex shape model Pole orientation Pole orientation Absolute magnitude Absolute magnitude Diameter Diameter Internal structure constraints Internal structure constraints Rotation periods Rotation periods Axis ratios Axis ratios Convex shape model Convex shape model Pole orientation Pole orientation Absolute magnitude Absolute magnitude Diameter Diameter Internal structure constraints Internal structure constraints

8. Nick Moskovitz | Physical Properties of Potentially Earth-Impacting Asteroids Thermal-IR Photometry Albedo Albedo Diameter Diameter Thermal properties: η,, k Thermal properties: η,, k Albedo Albedo Diameter Diameter Thermal properties: η,, k Thermal properties: η,, k (Trilling et al. 2010) (Mommert et al. 2014)

9. Nick Moskovitz | Physical Properties of Potentially Earth-Impacting Asteroids Visible & Near-IR (0.5-2.5 μ m) Spectroscopy Taxonomy Taxonomy Composition Composition Meteorite Analogs Meteorite Analogs Mineralogy Mineralogy Taxonomic albedo Taxonomic albedo Taxonomy Taxonomy Composition Composition Meteorite Analogs Meteorite Analogs Mineralogy Mineralogy Taxonomic albedo Taxonomic albedo

10. Nick Moskovitz | Physical Properties of Potentially Earth-Impacting Asteroids 3- μ m Spectroscopy Composition Composition Hydrated minerals Hydrated minerals Water ice Water ice Organics Organics Thermal properties Thermal properties Composition Composition Hydrated minerals Hydrated minerals Water ice Water ice Organics Organics Thermal properties Thermal properties (Takir & Emery 2012) (Rivkin & Emery 2010) H2OH2O Organics

11. Nick Moskovitz | Physical Properties of Potentially Earth-Impacting Asteroids Characterization Products Absolute magnitude Absolute magnitude Diameter Diameter Rotation periods Rotation periods Axis ratios Axis ratios Convex shape model Convex shape model Pole orientation Pole orientation Internal structure constraints Internal structure constraints Absolute magnitude Absolute magnitude Diameter Diameter Rotation periods Rotation periods Axis ratios Axis ratios Convex shape model Convex shape model Pole orientation Pole orientation Internal structure constraints Internal structure constraints Taxonomy Taxonomy Composition Composition Meteorite Analogs Meteorite Analogs Mineralogy Mineralogy Taxonomic albedo Taxonomic albedo Taxonomy Taxonomy Composition Composition Meteorite Analogs Meteorite Analogs Mineralogy Mineralogy Taxonomic albedo Taxonomic albedo Composition Composition Hydrated minerals Hydrated minerals Water ice Water ice Organics Organics Thermal properties Thermal properties Composition Composition Hydrated minerals Hydrated minerals Water ice Water ice Organics Organics Thermal properties Thermal properties Orbital Properties: a, e, i, Ω, ω Orbital Properties: a, e, i, Ω, ω Δv, MOID, v ∞ Δv, MOID, v ∞ Impact geometry Impact geometry Non-gravitational forces: Non-gravitational forces: Yarkovsky Yarkovsky Relativity Relativity Orbital Properties: a, e, i, Ω, ω Orbital Properties: a, e, i, Ω, ω Δv, MOID, v ∞ Δv, MOID, v ∞ Impact geometry Impact geometry Non-gravitational forces: Non-gravitational forces: Yarkovsky Yarkovsky Relativity Relativity Albedo Albedo Diameter Diameter Thermal properties: η,, k Thermal properties: η,, k Albedo Albedo Diameter Diameter Thermal properties: η,, k Thermal properties: η,, k Astrometry Visible Photometry Visible + NIR Spectroscopy 3- μm Spectroscopy Thermal-IR Photometry

12. Nick Moskovitz | Physical Properties of Potentially Earth-Impacting Asteroids Impact Frequency (yr) 10 6 10 4 10

13. Nick Moskovitz | Physical Properties of Potentially Earth-Impacting Asteroids Characterization demands urgency Large aperture facilities (>2 meters) necessary Ground-based characterization is essential precursor to mission planning/mitigation TimeMagnitudeEvent t = 0V~20 Catalina or PanSTARRs discovery t ~ 2-3 daysV~20Object designated (MPEC’d) t ~ 1-2 weeksV<21Spectroscopy t ~ 1 monthV < 22Photometry t ~ 1-2 monthsV < 24Astrometry t ~ several yearsV<23Next observing window Characterization Timeline

14. The Mission Accessible Near-Earth Object Survey Katheryn Neugent (Lowell) Michael Person (MIT) David Polishook (MIT) Henry Roe (Lowell) Rob Schottland (Kelis Innov.) Hosea Siu (MIT) Audrey Thirouin (Lowell) Cristina Thomas (GSFC) David Trilling (NAU) Larry Wasserman (Lowell) Mark Willman (IfA) Nick Moskovitz (PI, Lowell) Paul Abell (NASA/JSC) Dan Avner (Lowell) Richard Binzel (MIT) Brian Burt (Lowell, MIT) Eric Christensen (UA) Francesca DeMeo (CfA) Tom Endicott (UMass Boston) Will Grundy (Lowell) Mary Hinkle (NAU) Michael Mommert (NAU)

15. Nick Moskovitz | Physical Properties of Potentially Earth-Impacting Asteroids Goals Catalog physical properties of several hundred mission accessible sub-km NEOs Methods Rapid follow-up with large aperture (>4m) facilities → Astrometry + Photometry + Spectroscopy = comprehensive characterization Target selection 10 targets / month: Mission accessible → Δv < 7 km Size < 1 km M A N S

16. Nick Moskovitz | Physical Properties of Potentially Earth-Impacting Asteroids Impact Frequency (yr) 10 6 10 4 10

17. Nick Moskovitz | Physical Properties of Potentially Earth-Impacting Asteroids Impact Frequency (yr) 10 6 10 4 10

18. Nick Moskovitz | Physical Properties of Potentially Earth-Impacting Asteroids 2014 RC

19. Nick Moskovitz | Physical Properties of Potentially Earth-Impacting Asteroids Mary Hinkle (NAU) — Master’s Thesis C- types S- types Composition S-types = Ordinary chondrites; C-types = Carbonaceous chondrites OC ~80% of meteorites; S-types ~30% of km-scale NEOs Average S-type asteroid composition ≠ Average OC (see Stuart & Binzel 2004; Vernazza et al. 2008; Thomas et al. 2011)

20. Nick Moskovitz | Physical Properties of Potentially Earth-Impacting Asteroids (Binzel et al. 2010)

21. Nick Moskovitz | Physical Properties of Potentially Earth-Impacting Asteroids (Siu, Moskovitz & Binzel 2015, in revision) Rotation Frequency Dispersion Earth Encounter Distance (Lunar distances) Rotational Properties

22. Nick Moskovitz | Physical Properties of Potentially Earth-Impacting Asteroids Rotational Properties a/b Axis Ratio

23. Nick Moskovitz | Physical Properties of Potentially Earth-Impacting Asteroids http://manosobs.wordpress.com

24. Nick Moskovitz | Physical Properties of Potentially Earth-Impacting Asteroids ObjectAstrometryLight CurveShape ModelVis SpecNIR Spec http://manosobs.wordpress.com

25. Nick Moskovitz | Physical Properties of Potentially Earth-Impacting Asteroids Summary Discovery rates at historic highs Representative data sets provide probabilistic assessment of physical properties Composition: km-scale NEOs ≠ small NEOs ≠ meteorites C- types S- types Earth encounters alter physical properties Rotation Frequency Dispersion Earth Encounter Distance (Lunar distances)

26. M A N S Acknowledgment: NASA NEOO Grant NNX14AN82G + NSF AAPF Thank you! Nick Moskovitz nmosko@lowell.edu Nick Moskovitz nmosko@lowell.edu

27. Nick Moskovitz | Physical Properties of Potentially Earth-Impacting Asteroids