2_20701.txt c_ck17y020.txt C/2017 Y2 PANSTARRS C/2017 Y2 CK17Y020 C/2017 Y2 (PANSTARRS) 2020 11 04.5213 4.632884 1.000028 147.8817 66.0363 28.4279 2023 11 28 15.0 2000.0 4.0