Passage: The Celebes Sea is a piece of an ancient ocean basin that formed 42 million years ago in a locale removed from any landmass. By 20 million years ago, earth crust movement had moved the basin close enough to the Indonesian and Philippine volcanoes to receive emitted debris. By 10 million years ago the Celebes Sea was inundated with continental debris, including coal, which was shed from a growing young mountain on Borneo and the basin had docked against Eurasia.

Question: how long ago did the celebes sea form?
42 million years ago