Please note: all credit goes to HyperionSoup!
In this guide I will be showing you how to get the “Man on the Moon” achievement in Halo 3.
Man on the Moon Achievement Guide
This achievement is super easy, but easy to miss too.
To earn it, simply load up Forge on the map Standoff in Halo 3. Spawn in a sniper, and look at the moon that is in the skybox. It is as simple as that!
It can be finicky, so feel free to shoot at it or try with other weapons.