The project was called BOOMERanG because in the antarctic there is a circumpolar wind. The balloon went up, around and back, just like a boomerang!. The name for the project came later, and is clearly contrived to match.

Hawking once said that looking at the CMB was like looking at the face of God. The boomerang team took one of their sky maps and convolved with with a picture of a team member whoose name is Robert. They called it the face of Bob.