Round up the unusual suspects: Near-Earth Asteroid 17274 (2000 LC16) a plausible D-type parent body of the Tagish Lake meteorite
Gordon M. Gartrelle, Paul S. Hardersen, Matthew R.M. Izawa, Matthew C. Nowinski
Icarus
In Press, Journal Pre-proof, Available online 6 February 2021
“Highlights
• Spectral, visual, mathematical and Shkuratov radiative transfer analyses have determined near-Earth asteroid (NEA) 17274 (2000 LC16) to be a plausible parent body candidate for the Tagish Lake Meteorite (TLM).
• Eighty-six D-type asteroid spectra were evaluated against sixteen samples of TLM, five of which have detailed mineralogical characterizations.
• Shkuratov theory produces reasonable model fits to D-type asteroid spectra using mineralogy grounded in TLM samples measured by XRD and Rietveld refinement.
• Discrete Fréchet distance is a promising new metric for evaluating the wavelength-dependent spectral fit.”
“Asteroids are the origin point for most meteorites impacting Earth. Terrestrial meteorite samples provide evidence of what actually occurred in the early solar system at the formation location of the meteorite, and when it occurred. The ability to connect a meteorite sample to an asteroid parent body provides its starting location as a meteoroid. To date, only a handful of chondritic meteorite types have been credibly connected to an asteroid parent. For the past two decades, D-type asteroids, a dark, spectrally reddish, and featureless taxonomic type have been speculated to be the parent body of the tiny family of ungrouped chondrites. These include the Tagish Lake Meteorite (TLM), a ~ 4 m meteorite “fall” in Canada’s Yukon territory recovered in 2000. The quest to identify the TLM parent has been a baffling one as D-type asteroids are dominant among the Jovian Trojans, rare in main asteroid belt, and extremely rare in the inner asteroid belt as well as Near-Earth space.
This study employed Near Infrared (NIR) spectra (0.7–2.45 μm) of 86 D-types and a variety of analysis techniques including visual analysis, slope analysis, curve fitting, Fréchet analysis, dynamical analysis and Shkuratov radiative transfer theory to search for the TLM parent body. Sixteen TLM samples from the NASA Reflectance Experiment Laboratory (RELAB) plus five additional mineralogically well-constrained samples measured using X-ray diffraction (XRD) and Rietveld refinement were compared to D-type asteroid spectra. Our results indicate, out of several promising candidates, Near-Earth asteroid 17274 (2006 LC16), a ~ 3 km diameter Amor asteroid is a plausible parent body for TLM.”
