Tianwen-2 target asteroid (469219) Kamo’oalewa probably develops an Itokawa-compositional but ultra-highly space-weathered surfaceOPEN ACCESS
Pengfei Zhang, Guozheng Zhang, Zichen Wei, Mikael Granvik, Xiaoran Yan, Pengyue Wang, Qinwei Zhang, Ronghua Pang, Wen-Han Zhou, Te Jiang, Pierre Vernazza, Takahiro Hiroi, Edward Cloutis, Francesca DeMeo, Pierre Beck, Wing-Huen Ip, Marco Fenucci, Yongxiong Zhang, Michael Marsset, Yunbo Niu, Xuejin Lu, Xing Wu, Honglei Lin, Shoucun Hu, Bin Cheng, Haibin Zhao, Xiaobin Wang, Xiaoping Lu, Yonglong Zhang, Zongcheng Ling, Jiang Zhang, Sizhe Zhao, Cateline Lantz, Jooyeon Geem, Zhiping He, Juntao Wang, Liyong Zhou, Xiliang Zhang, Shijei Li, Sen Hu, Wei Yang, Xiongyao Li, Xiaoping Zhang, Jiahui Liu, Peng Zhang, Guang Zhang, Yangting Lin, Yang Li
under revision in Nature Communications
“China’s Tianwen-2 mission plans to return samples from a small, rapidly spinning Earth quasi-satellite (469219) Kamoʻoalewa. Previous studies linked Kamoʻoalewa to lunar composition and origin. Here, we propose another scenario. We reanalyzed the reflectance spectrum of Kamoʻoalewa and obtained an absorption band center at 1.001±0.028 μm (error is 1σ), consistent with LL chondrites. We then conducted space weathering (SW) experiments on meteorites and found that highly space-weathered LL chondrite powder (but not slab) successfully reproduced the reflectance spectrum of Kamoʻoalewa. We further traced the dynamical origin of Kamoʻoalewa and found that it probably originated from the ν6 secular resonance, and more specifically, the Flora family. Kamoʻoalewa exhibits a similar composition to Itokawa and 7 objects in the Flora family, but with a higher degree of space weathering. We, therefore, proposed that Kamoʻoalewa probably originated from the Flora family and developed an Itokawa-compositional, highly space-weathered, fine-regolith-dominated surface.”
