The entry in Japanese Final Fantasy IX Ultimania reads “Tera Daihoukai”, which translated with mechanical literalness means “Great Collapse of Terra” (daihoukai = the kanji from ookiku kuzurekowareru). Which is compatible with Kuja being a planet buster, since houkai means “collapse, crumble, disintegrate” and I found some Japanese sources using it to describe what happened to Alderaan (though less common than the generic hakai).
Mikoto: Kuzya no ano kyoudai na tikara wo mita desyou? Hitotu no sekai wo zibun no tikara dake de hakai sita...
“Did you see that power of Kuja’s? He destroyed one world with only his own power..."
Single Terran buildings easily dwarf even the Invincible, which has a wing span of 200 meters, making them significantly larger than any real human-made structure