TY - JOUR
T1 - Establishing Earth's Minimoon Population through Characterization of Asteroid 2020 CD3
AU - Fedorets, Grigori
AU - Micheli, Marco
AU - Jedicke, Robert
AU - Naidu, Shantanu P.
AU - Farnocchia, Davide
AU - Granvik, Mikael
AU - Moskovitz, Nicholas
AU - Schwamb, Megan E.
AU - Weryk, Robert
AU - Wierzchoś, Kacper
AU - Christensen, Eric
AU - Pruyne, Theodore
AU - Bottke, William F.
AU - Ye, Quanzhi
AU - Wainscoat, Richard
AU - Devogèle, Maxime
AU - Buchanan, Laura E.
AU - Djupvik, Anlaug Amanda
AU - Faes, Daniel M.
AU - Föhring, Dora
AU - Roediger, Joel
AU - Seccull, Tom
AU - Smith, Adam B.
PY - 2020/12/1
Y1 - 2020/12/1
N2 - We report on our detailed characterization of Earth's second known temporary natural satellite, or minimoon, asteroid 2020 CD3. An artificial origin can be ruled out based on its area-to-mass ratio and broadband photometry, which suggest that it is a silicate asteroid belonging to the S or V complex in asteroid taxonomy. The discovery of 2020 CD3 allows for the first time a comparison between known minimoons and theoretical models of their expected physical and dynamical properties. The estimated diameter of ${1.2}_{-0.2}^{+0.4}$ m and geocentric capture approximately a decade after the first known minimoon, 2006 RH120, are in agreement with theoretical predictions. The capture duration of 2020 CD3 of at least 2.7 yr is unexpectedly long compared to the simulation average, but it is in agreement with simulated minimoons that have close lunar encounters, providing additional support for the orbital models. 2020 CD3's atypical rotation period, significantly longer than theoretical predictions, suggests that our understanding of meter-scale asteroids needs revision. More discoveries and a detailed characterization of the population can be expected with the forthcoming Vera C. Rubin Observatory Legacy Survey of Space and Time.
AB - We report on our detailed characterization of Earth's second known temporary natural satellite, or minimoon, asteroid 2020 CD3. An artificial origin can be ruled out based on its area-to-mass ratio and broadband photometry, which suggest that it is a silicate asteroid belonging to the S or V complex in asteroid taxonomy. The discovery of 2020 CD3 allows for the first time a comparison between known minimoons and theoretical models of their expected physical and dynamical properties. The estimated diameter of ${1.2}_{-0.2}^{+0.4}$ m and geocentric capture approximately a decade after the first known minimoon, 2006 RH120, are in agreement with theoretical predictions. The capture duration of 2020 CD3 of at least 2.7 yr is unexpectedly long compared to the simulation average, but it is in agreement with simulated minimoons that have close lunar encounters, providing additional support for the orbital models. 2020 CD3's atypical rotation period, significantly longer than theoretical predictions, suggests that our understanding of meter-scale asteroids needs revision. More discoveries and a detailed characterization of the population can be expected with the forthcoming Vera C. Rubin Observatory Legacy Survey of Space and Time.
UR - https://arxiv.org/abs/2011.10380
U2 - 10.3847/1538-3881/abc3bc
DO - 10.3847/1538-3881/abc3bc
M3 - Article
VL - 160
JO - Astronomical Journal
JF - Astronomical Journal
SN - 0004-6256
IS - 6
ER -
