TY - JOUR
T1 - PHYSICAL CHARACTERIZATION of ∼2 m DIAMETER NEAR-EARTH ASTEROID 2015 TC25
T2 - A POSSIBLE BOULDER from E-TYPE ASTEROID (44) NYSA
AU - Reddy, Vishnu
AU - Sanchez, Juan A.
AU - Bottke, William F.
AU - Thirouin, Audrey
AU - Rivera-Valentin, Edgard G.
AU - Kelley, Michael S.
AU - Ryan, William
AU - Cloutis, Edward A.
AU - Tegler, Stephen C.
AU - Ryan, Eileen V.
AU - Taylor, Patrick A.
AU - Richardson, James E.
AU - Moskovitz, Nicholas
AU - Le Corre, Lucille
N1 - Publisher Copyright:
© 2016. The American Astronomical Society. All rights reserved.
PY - 2016/12
Y1 - 2016/12
N2 - Small near-Earth asteroids (NEAs) (<20 m) are interesting, because they are progenitors for meteorites in our terrestrial collection. The physical characteristics of these small NEAs are crucial to our understanding of the effectiveness of our atmosphere in filtering low-strength impactors. In the past, the characterization of small NEAs has been a challenge, because of the difficulty in detecting them prior to close Earth flyby. In this study, we physically characterized the 2 m diameter NEA 2015 TC25 using ground-based optical, near-infrared and radar assets during a close flyby of the Earth (distance 128,000 km) in 2015 October 12. Our observations suggest that its surface composition is similar to aubrites, a rare class of high-albedo differentiated meteorites. Aubrites make up only 0.14% of all known meteorites in our terrestrial meteorite collection. 2015 TC25 is also a very fast rotator with a period of 133 6 s. We combined the spectral and dynamical properties of 2015 TC25 and found the best candidate source body in the inner main belt to be the 70 km diameter E-type asteroid (44) Nysa. We attribute the difference in spectral slope between the two objects to the lack of regolith on the surface of 2015 TC25. Using the albedo of E-type asteroids (50%-60%) we refine the diameter of 2015 TC25 to 2 m, making it one of the smallest NEAs ever to be characterized.
AB - Small near-Earth asteroids (NEAs) (<20 m) are interesting, because they are progenitors for meteorites in our terrestrial collection. The physical characteristics of these small NEAs are crucial to our understanding of the effectiveness of our atmosphere in filtering low-strength impactors. In the past, the characterization of small NEAs has been a challenge, because of the difficulty in detecting them prior to close Earth flyby. In this study, we physically characterized the 2 m diameter NEA 2015 TC25 using ground-based optical, near-infrared and radar assets during a close flyby of the Earth (distance 128,000 km) in 2015 October 12. Our observations suggest that its surface composition is similar to aubrites, a rare class of high-albedo differentiated meteorites. Aubrites make up only 0.14% of all known meteorites in our terrestrial meteorite collection. 2015 TC25 is also a very fast rotator with a period of 133 6 s. We combined the spectral and dynamical properties of 2015 TC25 and found the best candidate source body in the inner main belt to be the 70 km diameter E-type asteroid (44) Nysa. We attribute the difference in spectral slope between the two objects to the lack of regolith on the surface of 2015 TC25. Using the albedo of E-type asteroids (50%-60%) we refine the diameter of 2015 TC25 to 2 m, making it one of the smallest NEAs ever to be characterized.
KW - meteorites, meteors, meteoroids
KW - minor planets, asteroids: general
KW - techniques: spectroscopic
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U2 - 10.3847/0004-6256/152/6/162
DO - 10.3847/0004-6256/152/6/162
M3 - Article
AN - SCOPUS:85009154247
SN - 0004-6256
VL - 152
JO - Astronomical Journal
JF - Astronomical Journal
IS - 6
M1 - 162
ER -