The Professor Achievement
Collect all Artifacts.
There are a total of 41 artifacts you must collect in order to gain this achievement. There are different types of artifacts. They include Alien, Unitology, EarthGov, and S.C.A.F. You will want to follow a guide to get them all. You can check the stats in your progress and unlocks screen from the pause menu.
Click HERE for a guide containing all collectibles and side mission details.