Ground-Based Observations of NEO Encounters: 1998 QE2 and 2012 DA14
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Observations of NEO Encounters: 1998 QE2 and 2012 DA14 Nick Moskovitz NSF Postdoctoral Fellow MIT EAPS 2013 SBAG Washington, DC 11 July, 2013
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Ground-Based Observations of NEO Encounters: 1998 QE2 and 2012 DA14. Nick Moskovitz NSF Postdoctoral Fellow MIT EAPS. 2013 SBAG Washington, DC 11 July, 2013. Collaborators. Tom Endicott (UMass) Franck Marchis (SETI) Thomas Augesteijn (NOT) Carl Hergenrother (UA) - PowerPoint PPT Presentation
Transcript of Ground-Based Observations of NEO Encounters: 1998 QE2 and 2012 DA14
Ground-Based Observations of NEO
Encounters: 1998 QE2 and 2012
DA14
Ground-Based Observations of NEO
Encounters: 1998 QE2 and 2012
DA14
Nick MoskovitzNSF Postdoctoral FellowMIT EAPS
Nick MoskovitzNSF Postdoctoral FellowMIT EAPS
2013 SBAGWashington, DC
11 July, 2013
CollaboratorsRick Binzel (MIT)
Francesca DeMeo (MIT)
David Polishook (MIT)
Eileen Ryan (NM Tech)
Bill Ryan (NM Tech)
Tim Lister (LCOGT)
Rick Binzel (MIT)
Francesca DeMeo (MIT)
David Polishook (MIT)
Eileen Ryan (NM Tech)
Bill Ryan (NM Tech)
Tim Lister (LCOGT)
Tom Endicott (UMass)
Franck Marchis (SETI)
Thomas Augesteijn (NOT)
Carl Hergenrother (UA)
Bin Yang (IfA)
Tom Endicott (UMass)
Franck Marchis (SETI)
Thomas Augesteijn (NOT)
Carl Hergenrother (UA)
Bin Yang (IfA)
NEO Encounters
(JPL Horizons)
ΔMoon = 0.0025 AU = 60R♁
Geostationary = 6R♁
Roche Limit = 2-3R♁
Predictable thanks to exponential growth of known objects
→ Catalina, LINEAR, LONEOS, Spacewatch, NEAT, Pan-STARRS
(285263) 1998 QE2‣Passed at ~0.04 AU or 15x lunar distance on May 31, 2013
‣Diameter = 2.7km Albedo = 6% (Trilling et al. 2010)
‣Observed by Goldstone and Arecibo → Binary
(285263) 1998 QE2‣Passed at ~0.04 AU or 15x lunar distance on May 31, 2013
‣Diameter = 2.7km Albedo = 6% (Trilling et al. 2010)
‣Observed by Goldstone and Arecibo → Binary‣Rare spectral type for NEOs = Ch-type
Visible: Palomar Hale 200” (Mike Hicks/JPL)Near-IR: IRTF/SpeX
RELAB (Pieters & Hiroi 2004)
(285263) 1998 QE2Thermal EmissionTmax ~ 400 K
(285263) 1998 QE2Opposition-centered Orbital Longitude:
☍
(285263) 1998 QE2Opposition-centered Orbital Longitude:
Afternoon Morning
☍
(285263) 1998 QE2‣Evolution of thermal emission → Prograde rotation?
Low T
High T
Pre-opposition
Post-opposition
May 11
June 2 July 5
May 30 data courtesy of Ellen Howell (Arecibo) and colleagues Vervack, Fernandez, Magri and Nolan
May 30
2012 DA14‣Discovered Feb. 23, 2012 by La Sagra Sky Survey
‣40m asteroid passed at ~4R♁ on Feb. 15, 2013
(NASA/JPL, P. Chodas)
DA14: Encounter Predictions‣ Change in rotation
state‣ Tidal disruption or
mass loss‣ Induced seismic
shaking (Scheeres et al. 2005)Post-Encounter Rotation Period (hr)
20 25 30 35 40 45
(Richardson et al. 1998)
Max. Distance
Avg. Distance
Min. Distance
DA14: Spectroscopy‣ Visible spectra: Gemini/GMOS NOT/ALFOSC‣ Linked to CO/CV carbonaceous chondrites
or FeO-bearing spinel (CAIs)
(Bell 1988; Gaffey et al. 1993; Burbine et al.
2002)
(Sunshine et al. 2008)
DA14: Rotational light curve
Post Flyby
• Data from: Wise (Israel), VATT (Mt. Graham), Kitt Peak (Arizona),
Hereford (Arizona), Shefford (UK), Magdalena Ridge (New Mexico)
•Tumbling rotation state
Light curve fit:P1 = 6.35 hrP2 = 8.73 hr
DA14: Periodogram Analysis
8.9 hr6.3 hr
Light curve fit:P1 = 6.35 hrP2 = 8.73 hr
Post Flyby (2013)
DA14: Periodogram Analysis
Discovery (2012) Pre-Flyby (2013)
5.5 ± 1 hr
4.8 ± 1 hr
Post Flyby (2013)8.9 hr6.3
hr
Light curve fit:P1 = 6.35 hrP2 = 8.73 hr
1998 QE2
2012 DA14
‣Binary object passed at ~0.04 AU on May 31, 2013
‣Low-albedo → strong thermal emission in near-IR
‣Phase dependent variability ‣Passed at 4 Earth-radii on February 15, 2013
‣No clear evidence for spectroscopic changes
‣Possible suggestion of change in rotation state
IRTF NEO Rapid Response: Close Encounters of the Asteroid Kind
‣Multi-semester ToO program at NASA’s IRTF
‣Observe close encounters, TC3-like impactors, very low Δv objects
‣Rapid response (<48 hours) capability
PI: Nicholas Moskovitz (MIT)
Richard Binzel (MIT), Bobby Bus (UH), Tim Spahr (CfA), Steve Chesley (JPL) Francesca DeMeo (MIT), David Polishook (MIT)
(Polishook et al. 2012)
The Mission Accessible Near-Earth Object Survey (MANOS)
‣ Spectra, light curves, & astrometry for >300 sub-km, low Δv NEOs
‣ NOAO: 24 nights per semester for 3 years
‣ Assets:
PI: Nicholas Moskovitz (MIT)
Gemini-N Gemini-SKitt Peak 4m
SOAR 4m
LowellCTIO 1.3m
UH2.2m Magellan
David Trilling (NAU)Cristina Thomas (Goddard)
Will Grundy (Lowell)
Mark Willman (UH) Eric Christensen (UA)Henry Roe (Lowell)
Francesca DeMeo (MIT) David Polishook (MIT)Richard Binzel (MIT)
Michael Person (MIT) Michael Busch (NRAO)
