Comets Contains additional comets and enhancements to the ones that are included in the stock installation of Celestia 1P/Halley 19P/Borrelly 26P/Grigg-Skjellerup 67P/Churyumov-Gerasimenko 73P/Schwassmann–Wachmann 81P/Wild 96P/Machholz 103P/Hartley C/1680 V1 (Newton's Comet) C/1980 E1 (Bowell) C/1995 O1 (Hale-Bopp) C/2012 S1 (ISON) C/2013 A1 (Siding Spring) C/2014 UN271 (Bernardinelli-Bernstein) C/2017 K2 (PANSTARRS) C/2020 F3 (NEOWISE) C/2021 A1 (Leonard) C/2022 E3 (ZTF) C/2023 A3 (Tsuchinshan-ATLAS) C/2023 P1 (Nishimura) Comets 2021 D/1993 F2 (Shoemaker-Levy 9) Periodic Comets: 2P to 8P Periodic Comets: 10P to 18P Periodic Comets: 20D to 25D Periodic Comets: 27P to 66P Periodic Comets: 68P to 80P