Gameplay

Face on the Moon

From Halopedia, the Halo wiki

The face similar to the one in Containment.

The Face on the Moon is an Easter egg located in the Halo 3 multiplayer map Standoff. By getting a close look at the moon while in Standoff, a face can be seen along the lower-right edge -- the face of Chris Carney, a Bungie employee. This face is quite similar to the ones on the maps Containment and Beaver Creek in Halo 2.

One way to view it is to zoom in on it using a Sniper Rifle. Pan Cam can also be used in Theater to get very close to the moon.