(noun/verb) An event in an person's life where a ridiculously awesome fucking took place. An astrofuck typically occurs when all partners involved would admit that that particular fucking was their best yet. As a rule, you cannot use this word after your first time.
"Babe, you and I are going to astrofuck tonight."
"Dude, last night, right after the party, Jennifer and I astrofucked. It was awesome."