Asteroid 2020 CD3 was discovered on 2020 February 15 by the Catalina Sky Survey while it was temporarily captured in a geocentric orbit before escaping Earth’s Hill sphere on 2020 March 7. We searched archival images and found precoveries of 2020 CD3 from the Dark Energy Camera and Catalina Sky survey. The Dark Energy Camera images yielded three observations on 2019 January 17, while the Catalina Sky Survey images yielded four observations on 2019 January 24 from the Mt. Lemmon telescope and four observations on 2018 May 9 from the Mt. Bigelow telescope. These precovery observations allowed us to refine the orbit of 2020 CD3 and determine that it was captured in a geocentric orbit on 2017 September 15 after a close approach to the Moon at a distance of 11,974 10 km. We analyzed the trajectory of 2020 CD3 to look for potential Earth impacts within the next 100 years and find a ≳1% probability of an impact between 2061 and 2120 depending on nongravitational force model assumptions. The small size of 2020 CD3, about 1 to 2 m, makes any potential impact harmless.

小行星 2020 CD3 于 2020 年 2 月 15 日被 Catalina Sky Survey 发现，它在 2020 年 3 月 7 日逃离地球希尔球之前暂时在地心轨道上被捕获。我们搜索了档案图像，并从暗能量相机和 Catalina 中发现了 2020 CD3天空调查。暗能量相机图像在 2019 年 1 月 17 日产生了三个观测结果，而卡塔利娜巡天图像在 2019 年 1 月 24 日从山上产生了四个观测结果。莱蒙望远镜和 2018 年 5 月 9 日从山的四次观测。毕格罗望远镜。这些前期观测使我们能够改进 2020 CD3 的轨道，并确定它是在 2017 年 9 月 15 日以 11,974 10 公里的距离近距离接近月球后在地心轨道上捕获的。我们分析了 2020 CD3 的轨迹，以寻找未来 100 年内对地球的潜在影响，并根据非重力模型假设，发现 2061 年至 2120 年之间发生撞击的概率≳1%。2020 CD3 的体积小，大约 1 到 2 m，使任何潜在的影响都无害。