海王 かいおう せい がい天体 てんたいだったら
kaiōseiga i tentaidattara

Noun
Da Copula

The "-tara" conditional form ("if/when…") of 海王星外天体

1. If/when it were a trans-Neptunian object.; If/when it was a trans-Neptunian object.

Tara Conditional
Astronomy